diff --git a/UPGRADE-4.4.md b/UPGRADE-4.4.md
index b4fb6a0a8e248..aef34c47bd61d 100644
--- a/UPGRADE-4.4.md
+++ b/UPGRADE-4.4.md
@@ -18,8 +18,6 @@ Console
 Debug
 -----
 
- * Deprecated the `Debug` class, use the one from the `ErrorRenderer` component instead
- * Deprecated the `FlattenException` class, use the one from the `ErrorRenderer` component instead
  * Deprecated the component in favor of the `ErrorHandler` component
 
 Config
@@ -306,48 +304,38 @@ TwigBundle
    ```
 
  * Deprecated the `ExceptionController` and `PreviewErrorController` controllers, use `ErrorController` from the HttpKernel component instead
- * Deprecated all built-in error templates, use the error renderer mechanism of the `ErrorRenderer` component
+ * Deprecated all built-in error templates, use the error renderer mechanism of the `ErrorHandler` component
  * Deprecated loading custom error templates in non-html formats. Custom HTML error pages based on Twig keep working as before:
 
-   Before (`templates/bundles/TwigBundle/Exception/error.jsonld.twig`):
+   Before (`templates/bundles/TwigBundle/Exception/error.json.twig`):
    ```twig
    {
-       "@id": "https://example.com",
-       "@type": "error",
-       "@context": {
-           "title": "{{ status_text }}",
-           "code": {{ status_code }},
-           "message": "{{ exception.message }}"
-       }
+       "type": "https://example.com/error",
+       "title": "{{ status_text }}",
+       "status": {{ status_code }}
    }
    ```
 
-   After (`App\ErrorRenderer\JsonLdErrorRenderer`):
+   After (`App\Serializer\ProblemJsonNormalizer`):
    ```php
-   class JsonLdErrorRenderer implements ErrorRendererInterface
+   class ProblemJsonNormalizer implements NormalizerInterface
    {
-       public static function getFormat(): string
+       public function normalize($exception, $format = null, array $context = [])
        {
-           return 'jsonld';
+           return [
+               'type' => 'https://example.com/error',
+               'title' => $exception->getStatusText(),
+               'status' => $exception->getStatusCode(),
+           ];
        }
 
-       public function render(FlattenException $exception): string
+       public function supportsNormalization($data, $format = null)
        {
-           return json_encode([
-               '@id' => 'https://example.com',
-               '@type' => 'error',
-               '@context' => [
-                   'title' => $exception->getTitle(),
-                   'code' => $exception->getStatusCode(),
-                   'message' => $exception->getMessage(),
-               ],
-           ]);
+           return 'json' === $format && $data instanceof FlattenException;
        }
    }
    ```
 
-  Configure your rendering service tagging it with `error_renderer.renderer`.
-
 Validator
 ---------
 
diff --git a/UPGRADE-5.0.md b/UPGRADE-5.0.md
index 8fc53005b312b..ce4b127c3ebfb 100644
--- a/UPGRADE-5.0.md
+++ b/UPGRADE-5.0.md
@@ -57,8 +57,6 @@ Console
 Debug
 -----
 
- * Removed the `Debug` class, use the one from the `ErrorRenderer` component instead
- * Removed the `FlattenException` class, use the one from the `ErrorRenderer` component instead
  * Removed the component in favor of the `ErrorHandler` component
 
 DependencyInjection
diff --git a/composer.json b/composer.json
index 24bcc7650f761..a432a159c07fe 100644
--- a/composer.json
+++ b/composer.json
@@ -48,7 +48,6 @@
         "symfony/dom-crawler": "self.version",
         "symfony/dotenv": "self.version",
         "symfony/error-handler": "self.version",
-        "symfony/error-renderer": "self.version",
         "symfony/event-dispatcher": "self.version",
         "symfony/expression-language": "self.version",
         "symfony/filesystem": "self.version",
diff --git a/src/Symfony/Bridge/Twig/CHANGELOG.md b/src/Symfony/Bridge/Twig/CHANGELOG.md
index 4f460d298221f..71a30ae880d78 100644
--- a/src/Symfony/Bridge/Twig/CHANGELOG.md
+++ b/src/Symfony/Bridge/Twig/CHANGELOG.md
@@ -4,6 +4,7 @@ CHANGELOG
 4.4.0
 -----
 
+ * added a new `TwigErrorRenderer` for `html` format, integrated with the `ErrorHandler` component
  * marked all classes extending twig as `@final`
  * deprecated to pass `$rootDir` and `$fileLinkFormatter` as 5th and 6th argument respectively to the 
    `DebugCommand::__construct()` method, swap the variables position.
diff --git a/src/Symfony/Bundle/TwigBundle/ErrorRenderer/TwigHtmlErrorRenderer.php b/src/Symfony/Bridge/Twig/ErrorRenderer/TwigErrorRenderer.php
similarity index 63%
rename from src/Symfony/Bundle/TwigBundle/ErrorRenderer/TwigHtmlErrorRenderer.php
rename to src/Symfony/Bridge/Twig/ErrorRenderer/TwigErrorRenderer.php
index b9c876a273cce..9968b8ba8f334 100644
--- a/src/Symfony/Bundle/TwigBundle/ErrorRenderer/TwigHtmlErrorRenderer.php
+++ b/src/Symfony/Bridge/Twig/ErrorRenderer/TwigErrorRenderer.php
@@ -9,11 +9,11 @@
  * file that was distributed with this source code.
  */
 
-namespace Symfony\Bundle\TwigBundle\ErrorRenderer;
+namespace Symfony\Bridge\Twig\ErrorRenderer;
 
-use Symfony\Component\ErrorRenderer\ErrorRenderer\ErrorRendererInterface;
-use Symfony\Component\ErrorRenderer\ErrorRenderer\HtmlErrorRenderer;
-use Symfony\Component\ErrorRenderer\Exception\FlattenException;
+use Symfony\Component\ErrorHandler\ErrorRenderer\ErrorRendererInterface;
+use Symfony\Component\ErrorHandler\ErrorRenderer\HtmlErrorRenderer;
+use Symfony\Component\ErrorHandler\Exception\FlattenException;
 use Twig\Environment;
 use Twig\Error\LoaderError;
 use Twig\Loader\ExistsLoaderInterface;
@@ -24,50 +24,36 @@
  *
  * @author Yonel Ceruto <yonelceruto@gmail.com>
  */
-class TwigHtmlErrorRenderer implements ErrorRendererInterface
+class TwigErrorRenderer implements ErrorRendererInterface
 {
     private $twig;
-    private $htmlErrorRenderer;
+    private $fallbackErrorRenderer;
     private $debug;
 
-    public function __construct(Environment $twig, HtmlErrorRenderer $htmlErrorRenderer, bool $debug = false)
+    public function __construct(Environment $twig, HtmlErrorRenderer $fallbackErrorRenderer = null, bool $debug = false)
     {
         $this->twig = $twig;
-        $this->htmlErrorRenderer = $htmlErrorRenderer;
+        $this->fallbackErrorRenderer = $fallbackErrorRenderer ?? new HtmlErrorRenderer();
         $this->debug = $debug;
     }
 
     /**
      * {@inheritdoc}
      */
-    public static function getFormat(): string
+    public function render(\Throwable $exception): FlattenException
     {
-        return 'html';
-    }
-
-    /**
-     * {@inheritdoc}
-     */
-    public function render(FlattenException $exception): string
-    {
-        $debug = $this->debug && ($exception->getHeaders()['X-Debug'] ?? true);
-
-        if ($debug) {
-            return $this->htmlErrorRenderer->render($exception);
-        }
-
-        $template = $this->findTemplate($exception->getStatusCode());
+        $exception = $this->fallbackErrorRenderer->render($exception);
 
-        if (null === $template) {
-            return $this->htmlErrorRenderer->render($exception);
+        if ($this->debug || !$template = $this->findTemplate($exception->getStatusCode())) {
+            return $exception;
         }
 
-        return $this->twig->render($template, [
+        return $exception->setAsString($this->twig->render($template, [
             'legacy' => false, // to be removed in 5.0
             'exception' => $exception,
             'status_code' => $exception->getStatusCode(),
-            'status_text' => $exception->getTitle(),
-        ]);
+            'status_text' => $exception->getStatusText(),
+        ]));
     }
 
     private function findTemplate(int $statusCode): ?string
diff --git a/src/Symfony/Bridge/Twig/Mime/NotificationEmail.php b/src/Symfony/Bridge/Twig/Mime/NotificationEmail.php
index d1051596dd390..b5118b7f08c7b 100644
--- a/src/Symfony/Bridge/Twig/Mime/NotificationEmail.php
+++ b/src/Symfony/Bridge/Twig/Mime/NotificationEmail.php
@@ -11,7 +11,7 @@
 
 namespace Symfony\Bridge\Twig\Mime;
 
-use Symfony\Component\ErrorRenderer\Exception\FlattenException;
+use Symfony\Component\ErrorHandler\Exception\FlattenException;
 use Symfony\Component\Mime\Header\Headers;
 use Symfony\Component\Mime\Part\AbstractPart;
 use Twig\Extra\CssInliner\CssInlinerExtension;
diff --git a/src/Symfony/Bundle/TwigBundle/Tests/ErrorRenderer/TwigHtmlErrorRendererTest.php b/src/Symfony/Bridge/Twig/Tests/ErrorRenderer/TwigErrorRendererTest.php
similarity index 54%
rename from src/Symfony/Bundle/TwigBundle/Tests/ErrorRenderer/TwigHtmlErrorRendererTest.php
rename to src/Symfony/Bridge/Twig/Tests/ErrorRenderer/TwigErrorRendererTest.php
index fa04d363caf21..9febc61e61887 100644
--- a/src/Symfony/Bundle/TwigBundle/Tests/ErrorRenderer/TwigHtmlErrorRendererTest.php
+++ b/src/Symfony/Bridge/Twig/Tests/ErrorRenderer/TwigErrorRendererTest.php
@@ -9,21 +9,21 @@
  * file that was distributed with this source code.
  */
 
-namespace Symfony\Bundle\TwigBundle\Tests\ErrorRenderer;
+namespace Symfony\Bridge\Twig\Tests\ErrorRenderer;
 
 use PHPUnit\Framework\TestCase;
-use Symfony\Bundle\TwigBundle\ErrorRenderer\TwigHtmlErrorRenderer;
-use Symfony\Component\ErrorRenderer\ErrorRenderer\HtmlErrorRenderer;
-use Symfony\Component\ErrorRenderer\Exception\FlattenException;
+use Symfony\Bridge\Twig\ErrorRenderer\TwigErrorRenderer;
+use Symfony\Component\ErrorHandler\ErrorRenderer\HtmlErrorRenderer;
+use Symfony\Component\ErrorHandler\Exception\FlattenException;
 use Symfony\Component\HttpKernel\Exception\NotFoundHttpException;
 use Twig\Environment;
 use Twig\Loader\ArrayLoader;
 
-class TwigHtmlErrorRendererTest extends TestCase
+class TwigErrorRendererTest extends TestCase
 {
     public function testFallbackToNativeRendererIfDebugOn()
     {
-        $exception = FlattenException::createFromThrowable(new \Exception());
+        $exception = new \Exception();
 
         $twig = $this->createMock(Environment::class);
         $nativeRenderer = $this->createMock(HtmlErrorRenderer::class);
@@ -33,12 +33,12 @@ public function testFallbackToNativeRendererIfDebugOn()
             ->with($exception)
         ;
 
-        (new TwigHtmlErrorRenderer($twig, $nativeRenderer, true))->render($exception);
+        (new TwigErrorRenderer($twig, $nativeRenderer, true))->render(new \Exception());
     }
 
     public function testFallbackToNativeRendererIfCustomTemplateNotFound()
     {
-        $exception = FlattenException::createFromThrowable(new NotFoundHttpException());
+        $exception = new NotFoundHttpException();
 
         $twig = new Environment(new ArrayLoader([]));
 
@@ -47,27 +47,19 @@ public function testFallbackToNativeRendererIfCustomTemplateNotFound()
             ->expects($this->once())
             ->method('render')
             ->with($exception)
+            ->willReturn(FlattenException::createFromThrowable($exception))
         ;
 
-        (new TwigHtmlErrorRenderer($twig, $nativeRenderer, false))->render($exception);
+        (new TwigErrorRenderer($twig, $nativeRenderer, false))->render($exception);
     }
 
     public function testRenderCustomErrorTemplate()
     {
-        $exception = FlattenException::createFromThrowable(new NotFoundHttpException());
-
         $twig = new Environment(new ArrayLoader([
             '@Twig/Exception/error404.html.twig' => '<h1>Page Not Found</h1>',
         ]));
+        $exception = (new TwigErrorRenderer($twig))->render(new NotFoundHttpException());
 
-        $nativeRenderer = $this->createMock(HtmlErrorRenderer::class);
-        $nativeRenderer
-            ->expects($this->never())
-            ->method('render')
-        ;
-
-        $content = (new TwigHtmlErrorRenderer($twig, $nativeRenderer, false))->render($exception);
-
-        $this->assertSame('<h1>Page Not Found</h1>', $content);
+        $this->assertSame('<h1>Page Not Found</h1>', $exception->getAsString());
     }
 }
diff --git a/src/Symfony/Bridge/Twig/composer.json b/src/Symfony/Bridge/Twig/composer.json
index 563b82327fbb3..ef493d86cb053 100644
--- a/src/Symfony/Bridge/Twig/composer.json
+++ b/src/Symfony/Bridge/Twig/composer.json
@@ -24,10 +24,11 @@
         "egulias/email-validator": "^2.1.10",
         "symfony/asset": "^3.4|^4.0|^5.0",
         "symfony/dependency-injection": "^3.4|^4.0|^5.0",
+        "symfony/error-handler": "^4.4|^5.0",
         "symfony/finder": "^3.4|^4.0|^5.0",
         "symfony/form": "^4.4|^5.0",
         "symfony/http-foundation": "^4.3|^5.0",
-        "symfony/http-kernel": "^3.4|^4.0",
+        "symfony/http-kernel": "^4.4",
         "symfony/mime": "^4.3|^5.0",
         "symfony/polyfill-intl-icu": "~1.0",
         "symfony/routing": "^3.4|^4.0|^5.0",
diff --git a/src/Symfony/Bundle/FrameworkBundle/DependencyInjection/Compiler/UnusedTagsPass.php b/src/Symfony/Bundle/FrameworkBundle/DependencyInjection/Compiler/UnusedTagsPass.php
index 7ee9e12c0afc5..e21550115b295 100644
--- a/src/Symfony/Bundle/FrameworkBundle/DependencyInjection/Compiler/UnusedTagsPass.php
+++ b/src/Symfony/Bundle/FrameworkBundle/DependencyInjection/Compiler/UnusedTagsPass.php
@@ -32,7 +32,6 @@ class UnusedTagsPass implements CompilerPassInterface
         'controller.service_arguments',
         'config_cache.resource_checker',
         'data_collector',
-        'error_renderer.renderer',
         'form.type',
         'form.type_extension',
         'form.type_guesser',
diff --git a/src/Symfony/Bundle/FrameworkBundle/FrameworkBundle.php b/src/Symfony/Bundle/FrameworkBundle/FrameworkBundle.php
index 173165b03eb4a..ed85fa2ea7586 100644
--- a/src/Symfony/Bundle/FrameworkBundle/FrameworkBundle.php
+++ b/src/Symfony/Bundle/FrameworkBundle/FrameworkBundle.php
@@ -33,7 +33,6 @@
 use Symfony\Component\DependencyInjection\Compiler\RegisterReverseContainerPass;
 use Symfony\Component\DependencyInjection\ContainerBuilder;
 use Symfony\Component\ErrorHandler\ErrorHandler;
-use Symfony\Component\ErrorRenderer\DependencyInjection\ErrorRendererPass;
 use Symfony\Component\EventDispatcher\DependencyInjection\RegisterListenersPass;
 use Symfony\Component\Form\DependencyInjection\FormPass;
 use Symfony\Component\HttpClient\DependencyInjection\HttpClientPass;
@@ -92,7 +91,6 @@ public function build(ContainerBuilder $container)
             KernelEvents::FINISH_REQUEST,
         ];
 
-        $container->addCompilerPass(new ErrorRendererPass());
         $container->addCompilerPass(new LoggerPass(), PassConfig::TYPE_BEFORE_OPTIMIZATION, -32);
         $container->addCompilerPass(new RegisterControllerArgumentLocatorsPass());
         $container->addCompilerPass(new RemoveEmptyControllerArgumentLocatorsPass(), PassConfig::TYPE_BEFORE_REMOVING);
diff --git a/src/Symfony/Bundle/FrameworkBundle/Resources/config/console.xml b/src/Symfony/Bundle/FrameworkBundle/Resources/config/console.xml
index 73b9eff6fe426..7276892940acb 100644
--- a/src/Symfony/Bundle/FrameworkBundle/Resources/config/console.xml
+++ b/src/Symfony/Bundle/FrameworkBundle/Resources/config/console.xml
@@ -194,12 +194,6 @@
             <tag name="console.command" command="debug:form" />
         </service>
 
-        <service id="console.command.error_renderer_debug" class="Symfony\Component\ErrorRenderer\Command\DebugCommand">
-            <argument type="collection" /> <!-- All error renderers are injected here by ErrorRendererPass -->
-            <argument type="service" id="debug.file_link_formatter" on-invalid="null" />
-            <tag name="console.command" command="debug:error-renderer" />
-        </service>
-
         <service id="console.command.secrets_set" class="Symfony\Bundle\FrameworkBundle\Command\SecretsSetCommand">
             <argument type="service" id="secrets.vault" />
             <argument type="service" id="secrets.local_vault" on-invalid="ignore" />
diff --git a/src/Symfony/Bundle/FrameworkBundle/Resources/config/error_renderer.xml b/src/Symfony/Bundle/FrameworkBundle/Resources/config/error_renderer.xml
index 4e3fc596f943c..af80a51d3f67b 100644
--- a/src/Symfony/Bundle/FrameworkBundle/Resources/config/error_renderer.xml
+++ b/src/Symfony/Bundle/FrameworkBundle/Resources/config/error_renderer.xml
@@ -5,12 +5,7 @@
            xsi:schemaLocation="http://symfony.com/schema/dic/services https://symfony.com/schema/dic/services/services-1.0.xsd">
 
     <services>
-        <service id="error_renderer" class="Symfony\Component\ErrorRenderer\DependencyInjection\LazyLoadingErrorRenderer">
-            <argument /> <!-- error renderer locator -->
-        </service>
-
-        <service id="error_renderer.renderer.html" class="Symfony\Component\ErrorRenderer\ErrorRenderer\HtmlErrorRenderer">
-            <tag name="error_renderer.renderer" />
+        <service id="error_handler.error_renderer.html" class="Symfony\Component\ErrorHandler\ErrorRenderer\HtmlErrorRenderer">
             <argument>%kernel.debug%</argument>
             <argument>%kernel.charset%</argument>
             <argument type="service" id="debug.file_link_formatter" on-invalid="null" />
@@ -19,21 +14,19 @@
             <argument type="service" id="logger" on-invalid="null" />
         </service>
 
-        <service id="error_renderer.renderer.json" class="Symfony\Component\ErrorRenderer\ErrorRenderer\JsonErrorRenderer">
-            <tag name="error_renderer.renderer" />
-            <argument>%kernel.debug%</argument>
+        <service id="error_handler.error_renderer.serializer" class="Symfony\Component\ErrorHandler\ErrorRenderer\SerializerErrorRenderer">
+            <argument type="service" id="serializer" />
+            <argument type="service">
+                <service>
+                    <factory class="Symfony\Component\ErrorHandler\ErrorRenderer\SerializerErrorRenderer" method="getPreferredFormat" />
+                    <argument type="service" id="request_stack" />
+                </service>
+            </argument>
+            <argument type="service" id="error_renderer.html" />
         </service>
 
-        <service id="error_renderer.renderer.xml" class="Symfony\Component\ErrorRenderer\ErrorRenderer\XmlErrorRenderer">
-            <tag name="error_renderer.renderer" format="atom" />
-            <tag name="error_renderer.renderer" />
-            <argument>%kernel.debug%</argument>
-            <argument>%kernel.charset%</argument>
-        </service>
-
-        <service id="error_renderer.renderer.txt" class="Symfony\Component\ErrorRenderer\ErrorRenderer\TxtErrorRenderer">
-            <tag name="error_renderer.renderer" />
-            <argument>%kernel.debug%</argument>
-        </service>
+        <service id="error_renderer.html" alias="error_handler.error_renderer.html" />
+        <service id="error_renderer.serializer" alias="error_handler.error_renderer.serializer" />
+        <service id="error_renderer" alias="error_renderer.html" />
     </services>
 </container>
diff --git a/src/Symfony/Bundle/FrameworkBundle/Resources/config/serializer.xml b/src/Symfony/Bundle/FrameworkBundle/Resources/config/serializer.xml
index 23da8b07bcb04..4698c505930a3 100644
--- a/src/Symfony/Bundle/FrameworkBundle/Resources/config/serializer.xml
+++ b/src/Symfony/Bundle/FrameworkBundle/Resources/config/serializer.xml
@@ -12,6 +12,8 @@
     <services>
         <defaults public="false" />
 
+        <service id="error_renderer" alias="error_renderer.serializer" />
+
         <service id="serializer" class="Symfony\Component\Serializer\Serializer" public="true">
             <argument type="collection" />
             <argument type="collection" />
@@ -59,6 +61,12 @@
             <tag name="serializer.normalizer" priority="-900" />
         </service>
 
+        <service id="serializer.normalizer.problem" class="Symfony\Component\Serializer\Normalizer\ProblemNormalizer">
+            <argument>%kernel.debug%</argument>
+            <!-- Run before serializer.normalizer.object -->
+            <tag name="serializer.normalizer" priority="-890" />
+        </service>
+
         <service id="serializer.normalizer.object" class="Symfony\Component\Serializer\Normalizer\ObjectNormalizer">
             <argument type="service" id="serializer.mapping.class_metadata_factory" />
             <argument type="service" id="serializer.name_converter.metadata_aware" />
diff --git a/src/Symfony/Bundle/FrameworkBundle/composer.json b/src/Symfony/Bundle/FrameworkBundle/composer.json
index e3faf21102453..46b1cd80e13ba 100644
--- a/src/Symfony/Bundle/FrameworkBundle/composer.json
+++ b/src/Symfony/Bundle/FrameworkBundle/composer.json
@@ -21,7 +21,6 @@
         "symfony/cache": "^4.4|^5.0",
         "symfony/config": "^4.3.4|^5.0",
         "symfony/dependency-injection": "^4.4|^5.0",
-        "symfony/error-renderer": "^4.4|^5.0",
         "symfony/http-foundation": "^4.4|^5.0",
         "symfony/http-kernel": "^4.4",
         "symfony/polyfill-mbstring": "~1.0",
@@ -50,7 +49,7 @@
         "symfony/process": "^3.4|^4.0|^5.0",
         "symfony/security-csrf": "^3.4|^4.0|^5.0",
         "symfony/security-http": "^3.4|^4.0|^5.0",
-        "symfony/serializer": "^4.3|^5.0",
+        "symfony/serializer": "^4.4|^5.0",
         "symfony/stopwatch": "^3.4|^4.0|^5.0",
         "symfony/translation": "^4.4|^5.0",
         "symfony/templating": "^3.4|^4.0|^5.0",
diff --git a/src/Symfony/Bundle/SecurityBundle/Tests/Functional/JsonLoginTest.php b/src/Symfony/Bundle/SecurityBundle/Tests/Functional/JsonLoginTest.php
index 4fbdb27c65989..a69f5e591d1fa 100644
--- a/src/Symfony/Bundle/SecurityBundle/Tests/Functional/JsonLoginTest.php
+++ b/src/Symfony/Bundle/SecurityBundle/Tests/Functional/JsonLoginTest.php
@@ -70,6 +70,6 @@ public function testDefaultJsonLoginBadRequest()
 
         $this->assertSame(400, $response->getStatusCode());
         $this->assertSame('application/json', $response->headers->get('Content-Type'));
-        $this->assertSame(['title' => 'Bad Request', 'status' => 400, 'detail' => 'Whoops, looks like something went wrong.'], json_decode($response->getContent(), true));
+        $this->assertSame(['type' => 'https://tools.ietf.org/html/rfc2616#section-10', 'title' => 'An error occurred', 'status' => 400, 'detail' => 'Bad Request'], json_decode($response->getContent(), true));
     }
 }
diff --git a/src/Symfony/Bundle/SecurityBundle/Tests/Functional/app/JsonLogin/config.yml b/src/Symfony/Bundle/SecurityBundle/Tests/Functional/app/JsonLogin/config.yml
index d6ed10e896ff9..3522f27f13898 100644
--- a/src/Symfony/Bundle/SecurityBundle/Tests/Functional/app/JsonLogin/config.yml
+++ b/src/Symfony/Bundle/SecurityBundle/Tests/Functional/app/JsonLogin/config.yml
@@ -1,6 +1,9 @@
 imports:
     - { resource: ./../config/framework.yml }
 
+framework:
+    serializer: ~
+
 security:
     encoders:
         Symfony\Component\Security\Core\User\User: plaintext
diff --git a/src/Symfony/Bundle/SecurityBundle/composer.json b/src/Symfony/Bundle/SecurityBundle/composer.json
index 7f3a55477b095..c9202bad57b70 100644
--- a/src/Symfony/Bundle/SecurityBundle/composer.json
+++ b/src/Symfony/Bundle/SecurityBundle/composer.json
@@ -35,6 +35,7 @@
         "symfony/form": "^3.4|^4.0|^5.0",
         "symfony/framework-bundle": "^4.4|^5.0",
         "symfony/http-foundation": "^3.4|^4.0|^5.0",
+        "symfony/serializer": "^4.4|^5.0",
         "symfony/translation": "^3.4|^4.0|^5.0",
         "symfony/twig-bundle": "^4.4|^5.0",
         "symfony/twig-bridge": "^3.4|^4.0|^5.0",
diff --git a/src/Symfony/Bundle/TwigBundle/CHANGELOG.md b/src/Symfony/Bundle/TwigBundle/CHANGELOG.md
index 99b14db8d52c5..780c46466dd36 100644
--- a/src/Symfony/Bundle/TwigBundle/CHANGELOG.md
+++ b/src/Symfony/Bundle/TwigBundle/CHANGELOG.md
@@ -6,8 +6,7 @@ CHANGELOG
 
  * marked the `TemplateIterator` as `internal`
  * added HTML comment to beginning and end of `exception_full.html.twig`
- * added a new `TwigHtmlErrorRenderer` for `html` format, integrated with the `ErrorRenderer` component 
- * deprecated `ExceptionController` and `PreviewErrorController` controllers, use `ErrorController` from the `HttpKernel` component instead 
+ * deprecated `ExceptionController` and `PreviewErrorController` controllers, use `ErrorController` from the `HttpKernel` component instead
  * deprecated all built-in error templates in favor of the new error renderer mechanism
  * deprecated `twig.exception_controller` configuration option, set it to "null" and use `framework.error_controller` configuration instead
 
diff --git a/src/Symfony/Bundle/TwigBundle/Resources/config/twig.xml b/src/Symfony/Bundle/TwigBundle/Resources/config/twig.xml
index fa886981e9000..425acdadef5a0 100644
--- a/src/Symfony/Bundle/TwigBundle/Resources/config/twig.xml
+++ b/src/Symfony/Bundle/TwigBundle/Resources/config/twig.xml
@@ -162,10 +162,9 @@
             <argument /> <!-- runtime locator -->
         </service>
 
-        <service id="twig.error_renderer.html" class="Symfony\Bundle\TwigBundle\ErrorRenderer\TwigHtmlErrorRenderer">
-            <tag name="error_renderer.renderer" priority="1" />
+        <service id="twig.error_renderer.html" class="Symfony\Bridge\Twig\ErrorRenderer\TwigErrorRenderer" decorates="error_renderer.html">
             <argument type="service" id="twig" />
-            <argument type="service" id="error_renderer.renderer.html" />
+            <argument type="service" id="twig.error_renderer.html.inner" />
             <argument>%kernel.debug%</argument>
         </service>
     </services>
diff --git a/src/Symfony/Bundle/TwigBundle/Tests/DependencyInjection/TwigExtensionTest.php b/src/Symfony/Bundle/TwigBundle/Tests/DependencyInjection/TwigExtensionTest.php
index 01abbd166715d..1a991ba694904 100644
--- a/src/Symfony/Bundle/TwigBundle/Tests/DependencyInjection/TwigExtensionTest.php
+++ b/src/Symfony/Bundle/TwigBundle/Tests/DependencyInjection/TwigExtensionTest.php
@@ -23,6 +23,7 @@
 use Symfony\Component\DependencyInjection\Loader\YamlFileLoader;
 use Symfony\Component\DependencyInjection\ParameterBag\ParameterBag;
 use Symfony\Component\DependencyInjection\Reference;
+use Symfony\Component\ErrorHandler\ErrorRenderer\HtmlErrorRenderer;
 
 class TwigExtensionTest extends TestCase
 {
@@ -302,6 +303,7 @@ public function testRuntimeLoader()
         $container->register('templating.locator', 'FooClass');
         $container->register('templating.name_parser', 'FooClass');
         $container->register('foo', '%foo%')->addTag('twig.runtime');
+        $container->register('error_renderer.html', HtmlErrorRenderer::class);
         $container->addCompilerPass(new RuntimeLoaderPass(), PassConfig::TYPE_BEFORE_REMOVING);
         $container->getCompilerPassConfig()->setRemovingPasses([]);
         $container->getCompilerPassConfig()->setAfterRemovingPasses([]);
diff --git a/src/Symfony/Bundle/TwigBundle/Tests/Functional/EmptyAppTest.php b/src/Symfony/Bundle/TwigBundle/Tests/Functional/EmptyAppTest.php
index 55851f1d6992e..a7f3bc27dadec 100644
--- a/src/Symfony/Bundle/TwigBundle/Tests/Functional/EmptyAppTest.php
+++ b/src/Symfony/Bundle/TwigBundle/Tests/Functional/EmptyAppTest.php
@@ -15,7 +15,7 @@
 use Symfony\Bundle\TwigBundle\TwigBundle;
 use Symfony\Component\Config\Loader\LoaderInterface;
 use Symfony\Component\DependencyInjection\ContainerBuilder;
-use Symfony\Component\ErrorRenderer\ErrorRenderer;
+use Symfony\Component\ErrorHandler\ErrorRenderer\HtmlErrorRenderer;
 use Symfony\Component\Filesystem\Filesystem;
 use Symfony\Component\HttpKernel\Kernel;
 
@@ -65,7 +65,8 @@ public function registerContainerConfiguration(LoaderInterface $loader)
                 'strict_variables' => false,
                 'exception_controller' => null,
             ]);
-            $container->register('error_renderer', ErrorRenderer::class);
+            $container->register('error_renderer.html', HtmlErrorRenderer::class);
+            $container->setAlias('error_renderer', 'error_renderer.html');
             $container->setParameter('debug.file_link_format', null);
         });
     }
diff --git a/src/Symfony/Bundle/TwigBundle/composer.json b/src/Symfony/Bundle/TwigBundle/composer.json
index c10735b578eb5..d9bf24fa488f8 100644
--- a/src/Symfony/Bundle/TwigBundle/composer.json
+++ b/src/Symfony/Bundle/TwigBundle/composer.json
@@ -17,7 +17,6 @@
     ],
     "require": {
         "php": "^7.1.3",
-        "symfony/error-renderer": "^4.4|^5.0",
         "symfony/twig-bridge": "^4.4|^5.0",
         "symfony/http-foundation": "^4.3|^5.0",
         "symfony/http-kernel": "^4.4",
diff --git a/src/Symfony/Bundle/WebProfilerBundle/Controller/ExceptionController.php b/src/Symfony/Bundle/WebProfilerBundle/Controller/ExceptionController.php
index 168f2ca2ceeb0..095d65486aae7 100644
--- a/src/Symfony/Bundle/WebProfilerBundle/Controller/ExceptionController.php
+++ b/src/Symfony/Bundle/WebProfilerBundle/Controller/ExceptionController.php
@@ -11,7 +11,7 @@
 
 namespace Symfony\Bundle\WebProfilerBundle\Controller;
 
-use Symfony\Component\ErrorRenderer\ErrorRenderer\HtmlErrorRenderer;
+use Symfony\Component\ErrorHandler\ErrorRenderer\HtmlErrorRenderer;
 use Symfony\Component\HttpFoundation\Response;
 use Symfony\Component\HttpKernel\Debug\FileLinkFormatter;
 use Symfony\Component\HttpKernel\Exception\NotFoundHttpException;
@@ -42,11 +42,7 @@ public function __construct(Profiler $profiler = null, Environment $twig, bool $
         $this->profiler = $profiler;
         $this->twig = $twig;
         $this->debug = $debug;
-        $this->errorRenderer = $errorRenderer;
-
-        if (null === $errorRenderer) {
-            $this->errorRenderer = new HtmlErrorRenderer($debug, $this->twig->getCharset(), $fileLinkFormat);
-        }
+        $this->errorRenderer = $errorRenderer ?? new HtmlErrorRenderer($debug, $this->twig->getCharset(), $fileLinkFormat);
     }
 
     /**
diff --git a/src/Symfony/Bundle/WebProfilerBundle/Controller/ExceptionPanelController.php b/src/Symfony/Bundle/WebProfilerBundle/Controller/ExceptionPanelController.php
index cff1f39400c16..4941208c88bc2 100644
--- a/src/Symfony/Bundle/WebProfilerBundle/Controller/ExceptionPanelController.php
+++ b/src/Symfony/Bundle/WebProfilerBundle/Controller/ExceptionPanelController.php
@@ -11,7 +11,7 @@
 
 namespace Symfony\Bundle\WebProfilerBundle\Controller;
 
-use Symfony\Component\ErrorRenderer\ErrorRenderer\HtmlErrorRenderer;
+use Symfony\Component\ErrorHandler\ErrorRenderer\HtmlErrorRenderer;
 use Symfony\Component\HttpFoundation\Response;
 use Symfony\Component\HttpKernel\Exception\NotFoundHttpException;
 use Symfony\Component\HttpKernel\Profiler\Profiler;
@@ -25,12 +25,12 @@
  */
 class ExceptionPanelController
 {
-    private $htmlErrorRenderer;
+    private $errorRenderer;
     private $profiler;
 
-    public function __construct(HtmlErrorRenderer $htmlErrorRenderer, ?Profiler $profiler)
+    public function __construct(HtmlErrorRenderer $errorRenderer, Profiler $profiler = null)
     {
-        $this->htmlErrorRenderer = $htmlErrorRenderer;
+        $this->errorRenderer = $errorRenderer;
         $this->profiler = $profiler;
     }
 
@@ -48,7 +48,7 @@ public function body(string $token): Response
             ->getException()
         ;
 
-        return new Response($this->htmlErrorRenderer->getBody($exception), 200, ['Content-Type' => 'text/html']);
+        return new Response($this->errorRenderer->getBody($exception), 200, ['Content-Type' => 'text/html']);
     }
 
     /**
@@ -56,6 +56,6 @@ public function body(string $token): Response
      */
     public function stylesheet(): Response
     {
-        return new Response($this->htmlErrorRenderer->getStylesheet(), 200, ['Content-Type' => 'text/css']);
+        return new Response($this->errorRenderer->getStylesheet(), 200, ['Content-Type' => 'text/css']);
     }
 }
diff --git a/src/Symfony/Bundle/WebProfilerBundle/Resources/config/profiler.xml b/src/Symfony/Bundle/WebProfilerBundle/Resources/config/profiler.xml
index 0d68bf00b04c6..89ecca5baf8e0 100644
--- a/src/Symfony/Bundle/WebProfilerBundle/Resources/config/profiler.xml
+++ b/src/Symfony/Bundle/WebProfilerBundle/Resources/config/profiler.xml
@@ -27,12 +27,12 @@
             <argument type="service" id="twig" />
             <argument>%kernel.debug%</argument>
             <argument type="service" id="debug.file_link_formatter" />
-            <argument type="service" id="error_renderer.renderer.html" />
+            <argument type="service" id="error_handler.error_renderer.html" />
             <deprecated>The "%service_id%" service is deprecated since Symfony 4.4, use the "web_profiler.controller.exception_panel" service instead.</deprecated>
         </service>
 
         <service id="web_profiler.controller.exception_panel" class="Symfony\Bundle\WebProfilerBundle\Controller\ExceptionPanelController" public="true">
-            <argument type="service" id="error_renderer.renderer.html" />
+            <argument type="service" id="error_handler.error_renderer.html" />
             <argument type="service" id="profiler" on-invalid="null" />
         </service>
 
diff --git a/src/Symfony/Bundle/WebProfilerBundle/Tests/DependencyInjection/WebProfilerExtensionTest.php b/src/Symfony/Bundle/WebProfilerBundle/Tests/DependencyInjection/WebProfilerExtensionTest.php
index 9934077cf1aac..b94ef8045b684 100644
--- a/src/Symfony/Bundle/WebProfilerBundle/Tests/DependencyInjection/WebProfilerExtensionTest.php
+++ b/src/Symfony/Bundle/WebProfilerBundle/Tests/DependencyInjection/WebProfilerExtensionTest.php
@@ -17,7 +17,7 @@
 use Symfony\Component\DependencyInjection\ContainerBuilder;
 use Symfony\Component\DependencyInjection\Definition;
 use Symfony\Component\DependencyInjection\Reference;
-use Symfony\Component\ErrorRenderer\ErrorRenderer\HtmlErrorRenderer;
+use Symfony\Component\ErrorHandler\ErrorRenderer\HtmlErrorRenderer;
 use Symfony\Component\EventDispatcher\DependencyInjection\RegisterListenersPass;
 use Symfony\Component\EventDispatcher\EventDispatcher;
 
@@ -54,7 +54,7 @@ protected function setUp(): void
         $this->kernel = $this->getMockBuilder('Symfony\\Component\\HttpKernel\\KernelInterface')->getMock();
 
         $this->container = new ContainerBuilder();
-        $this->container->register('error_renderer.renderer.html', HtmlErrorRenderer::class)->setPublic(true);
+        $this->container->register('error_handler.error_renderer.html', HtmlErrorRenderer::class)->setPublic(true);
         $this->container->register('event_dispatcher', EventDispatcher::class)->setPublic(true);
         $this->container->register('router', $this->getMockClass('Symfony\\Component\\Routing\\RouterInterface'))->setPublic(true);
         $this->container->register('twig', 'Twig\Environment')->setPublic(true);
diff --git a/src/Symfony/Bundle/WebProfilerBundle/composer.json b/src/Symfony/Bundle/WebProfilerBundle/composer.json
index bb131bea9f33c..e3f7bc010706d 100644
--- a/src/Symfony/Bundle/WebProfilerBundle/composer.json
+++ b/src/Symfony/Bundle/WebProfilerBundle/composer.json
@@ -18,7 +18,6 @@
     "require": {
         "php": "^7.1.3",
         "symfony/config": "^4.2|^5.0",
-        "symfony/error-renderer": "^4.4|^5.0",
         "symfony/http-kernel": "^4.4",
         "symfony/routing": "^3.4|^4.0|^5.0",
         "symfony/twig-bundle": "^4.2|^5.0",
diff --git a/src/Symfony/Component/Debug/CHANGELOG.md b/src/Symfony/Component/Debug/CHANGELOG.md
index b2e17f38211a8..989c1a72da7af 100644
--- a/src/Symfony/Component/Debug/CHANGELOG.md
+++ b/src/Symfony/Component/Debug/CHANGELOG.md
@@ -4,7 +4,7 @@ CHANGELOG
 4.4.0
 -----
 
- * deprecated `FlattenException`, use the `FlattenException` of the `ErrorRenderer` component
+ * deprecated `FlattenException`, use the `FlattenException` of the `ErrorHandler` component
  * deprecated the whole component in favor of the `ErrorHandler` component
 
 4.3.0
diff --git a/src/Symfony/Component/Debug/Exception/FlattenException.php b/src/Symfony/Component/Debug/Exception/FlattenException.php
index 4e213b1bd92ae..f55f71b0c9d25 100644
--- a/src/Symfony/Component/Debug/Exception/FlattenException.php
+++ b/src/Symfony/Component/Debug/Exception/FlattenException.php
@@ -21,7 +21,7 @@
  *
  * @author Fabien Potencier <fabien@symfony.com>
  *
- * @deprecated since Symfony 4.4, use Symfony\Component\ErrorRenderer\Exception\FlattenException instead.
+ * @deprecated since Symfony 4.4, use Symfony\Component\ErrorHandler\Exception\FlattenException instead.
  */
 class FlattenException
 {
diff --git a/src/Symfony/Component/ErrorHandler/BufferingLogger.php b/src/Symfony/Component/ErrorHandler/BufferingLogger.php
index 49c838f272cd0..16e433dedf898 100644
--- a/src/Symfony/Component/ErrorHandler/BufferingLogger.php
+++ b/src/Symfony/Component/ErrorHandler/BufferingLogger.php
@@ -34,4 +34,25 @@ public function cleanLogs(): array
 
         return $logs;
     }
+
+    public function __destruct()
+    {
+        foreach ($this->logs as [$level, $message, $context]) {
+            if (false !== strpos($message, '{')) {
+                foreach ($context as $key => $val) {
+                    if (null === $val || is_scalar($val) || (\is_object($val) && \is_callable([$val, '__toString']))) {
+                        $message = str_replace("{{$key}}", $val, $message);
+                    } elseif ($val instanceof \DateTimeInterface) {
+                        $message = str_replace("{{$key}}", $val->format(\DateTime::RFC3339), $message);
+                    } elseif (\is_object($val)) {
+                        $message = str_replace("{{$key}}", '[object '.\get_class($val).']', $message);
+                    } else {
+                        $message = str_replace("{{$key}}", '['.\gettype($val).']', $message);
+                    }
+                }
+            }
+
+            error_log(sprintf('%s [%s] %s', date(\DateTime::RFC3339), $level, $message));
+        }
+    }
 }
diff --git a/src/Symfony/Component/ErrorHandler/Debug.php b/src/Symfony/Component/ErrorHandler/Debug.php
index 6f75dbf60e38a..f95334e01ab58 100644
--- a/src/Symfony/Component/ErrorHandler/Debug.php
+++ b/src/Symfony/Component/ErrorHandler/Debug.php
@@ -18,39 +18,19 @@
  */
 class Debug
 {
-    private static $enabled = false;
-
-    /**
-     * Enables the debug tools.
-     *
-     * This method registers an error handler and an exception handler.
-     */
-    public static function enable(int $errorReportingLevel = E_ALL, bool $displayErrors = true): void
+    public static function enable(): ErrorHandler
     {
-        if (static::$enabled) {
-            return;
-        }
-
-        static::$enabled = true;
-
-        if (null !== $errorReportingLevel) {
-            error_reporting($errorReportingLevel);
-        } else {
-            error_reporting(E_ALL);
-        }
+        error_reporting(-1);
 
         if (!\in_array(\PHP_SAPI, ['cli', 'phpdbg'], true)) {
             ini_set('display_errors', 0);
-        } elseif ($displayErrors && (!filter_var(ini_get('log_errors'), FILTER_VALIDATE_BOOLEAN) || ini_get('error_log'))) {
+        } elseif (!filter_var(ini_get('log_errors'), FILTER_VALIDATE_BOOLEAN) || ini_get('error_log')) {
             // CLI - display errors only if they're not already logged to STDERR
             ini_set('display_errors', 1);
         }
-        if ($displayErrors) {
-            ErrorHandler::register(new ErrorHandler(new BufferingLogger()));
-        } else {
-            ErrorHandler::register()->throwAt(0, true);
-        }
 
         DebugClassLoader::enable();
+
+        return ErrorHandler::register(new ErrorHandler(new BufferingLogger()));
     }
 }
diff --git a/src/Symfony/Component/ErrorHandler/ErrorHandler.php b/src/Symfony/Component/ErrorHandler/ErrorHandler.php
index ab6df70bd8da9..6df9cdec22964 100644
--- a/src/Symfony/Component/ErrorHandler/ErrorHandler.php
+++ b/src/Symfony/Component/ErrorHandler/ErrorHandler.php
@@ -19,9 +19,9 @@
 use Symfony\Component\ErrorHandler\ErrorEnhancer\ErrorEnhancerInterface;
 use Symfony\Component\ErrorHandler\ErrorEnhancer\UndefinedFunctionErrorEnhancer;
 use Symfony\Component\ErrorHandler\ErrorEnhancer\UndefinedMethodErrorEnhancer;
+use Symfony\Component\ErrorHandler\ErrorRenderer\CliErrorRenderer;
+use Symfony\Component\ErrorHandler\ErrorRenderer\HtmlErrorRenderer;
 use Symfony\Component\ErrorHandler\Exception\SilencedErrorContext;
-use Symfony\Component\ErrorRenderer\ErrorRenderer\HtmlErrorRenderer;
-use Symfony\Component\ErrorRenderer\Exception\FlattenException;
 
 /**
  * A generic ErrorHandler for the PHP engine.
@@ -45,10 +45,8 @@
  *
  * @author Nicolas Grekas <p@tchwork.com>
  * @author Grégoire Pineau <lyrixx@lyrixx.info>
- *
- * @final since Symfony 4.3
  */
-class ErrorHandler
+final class ErrorHandler
 {
     private $levels = [
         E_DEPRECATED => 'Deprecated',
@@ -145,10 +143,8 @@ public static function register(self $handler = null, bool $replace = true): sel
                 $handler->setExceptionHandler($p);
                 $prev[0]->setExceptionHandler($p);
             }
-        } elseif (null === $prev && !\in_array(\PHP_SAPI, ['cli', 'phpdbg'], true)) {
-            $handler->setExceptionHandler([$handler, 'sendPhpResponse']);
         } else {
-            $handler->setExceptionHandler($prev);
+            $handler->setExceptionHandler($prev ?? [$handler, 'renderException']);
         }
 
         $handler->throwAt(E_ALL & $handler->thrownErrors, true);
@@ -280,7 +276,7 @@ public function setLoggers(array $loggers): array
     /**
      * Sets a user exception handler.
      *
-     * @param callable|null $handler A handler that must support \Throwable instances that will be called on Exception
+     * @param callable(\Throwable $e)|null $handler
      *
      * @return callable|null The previous exception handler
      */
@@ -583,11 +579,12 @@ public function handleException(\Throwable $exception)
         }
 
         $exceptionHandler = $this->exceptionHandler;
-        if ((!\is_array($exceptionHandler) || !$exceptionHandler[0] instanceof self || 'sendPhpResponse' !== $exceptionHandler[1]) && !\in_array(\PHP_SAPI, ['cli', 'phpdbg'], true)) {
-            $this->exceptionHandler = [$this, 'sendPhpResponse'];
-        } else {
+        $this->exceptionHandler = [$this, 'renderException'];
+
+        if (null === $exceptionHandler || $exceptionHandler === $this->exceptionHandler) {
             $this->exceptionHandler = null;
         }
+
         try {
             if (null !== $exceptionHandler) {
                 return $exceptionHandler($exception);
@@ -600,7 +597,14 @@ public function handleException(\Throwable $exception)
             throw $exception; // Give back $exception to the native handler
         }
 
-        $this->handleException($handlerException);
+        $loggedErrors = $this->loggedErrors;
+        $this->loggedErrors = $exception === $handlerException ? 0 : $this->loggedErrors;
+
+        try {
+            $this->handleException($handlerException);
+        } finally {
+            $this->loggedErrors = $loggedErrors;
+        }
     }
 
     /**
@@ -684,36 +688,26 @@ public static function handleFatalError(array $error = null): void
     }
 
     /**
-     * Sends the error associated with the given Exception as a plain PHP response.
+     * Renders the given exception.
      *
-     * As this method is mainly called during Kernel boot, where nothing is yet
-     * available, the Response content is always HTML.
+     * As this method is mainly called during boot where nothing is yet available,
+     * the output is always either HTML or CLI depending where PHP runs.
      */
-    private function sendPhpResponse(\Throwable $exception)
+    private function renderException(\Throwable $exception): void
     {
-        $charset = ini_get('default_charset') ?: 'UTF-8';
-        $statusCode = 500;
-        $headers = [];
-
-        if (class_exists(HtmlErrorRenderer::class)) {
-            $exception = FlattenException::createFromThrowable($exception);
-            $statusCode = $exception->getStatusCode();
-            $headers = $exception->getHeaders();
-            $response = (new HtmlErrorRenderer(0 !== $this->scopedErrors))->render($exception);
-        } else {
-            $message = htmlspecialchars($exception->getMessage(), ENT_COMPAT | ENT_SUBSTITUTE, $charset);
-            $response = sprintf('<!DOCTYPE html><html><head><meta charset="%s" /><meta name="robots" content="noindex,nofollow" /></head><body>%s</body></html>', $charset, $message);
-        }
+        $renderer = \in_array(\PHP_SAPI, ['cli', 'phpdbg'], true) ? new CliErrorRenderer() : new HtmlErrorRenderer(0 !== $this->scopedErrors);
+
+        $exception = $renderer->render($exception);
 
         if (!headers_sent()) {
-            header(sprintf('HTTP/1.0 %s', $statusCode));
-            foreach ($headers as $name => $value) {
+            http_response_code($exception->getStatusCode());
+
+            foreach ($exception->getHeaders() as $name => $value) {
                 header($name.': '.$value, false);
             }
-            header('Content-Type: text/html; charset='.$charset);
         }
 
-        echo $response;
+        echo $exception->getAsString();
     }
 
     /**
diff --git a/src/Symfony/Component/ErrorHandler/ErrorRenderer/CliErrorRenderer.php b/src/Symfony/Component/ErrorHandler/ErrorRenderer/CliErrorRenderer.php
new file mode 100644
index 0000000000000..aa132d1cfaccb
--- /dev/null
+++ b/src/Symfony/Component/ErrorHandler/ErrorRenderer/CliErrorRenderer.php
@@ -0,0 +1,46 @@
+<?php
+
+/*
+ * This file is part of the Symfony package.
+ *
+ * (c) Fabien Potencier <fabien@symfony.com>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace Symfony\Component\ErrorHandler\ErrorRenderer;
+
+use Symfony\Component\ErrorHandler\Exception\FlattenException;
+use Symfony\Component\VarDumper\Cloner\VarCloner;
+use Symfony\Component\VarDumper\Dumper\CliDumper;
+
+/**
+ * @author Nicolas Grekas <p@tchwork.com>
+ */
+class CliErrorRenderer implements ErrorRendererInterface
+{
+    /**
+     * {@inheritdoc}
+     */
+    public function render(\Throwable $exception): FlattenException
+    {
+        $cloner = new VarCloner();
+        $dumper = new class() extends CliDumper {
+            protected function supportsColors(): bool
+            {
+                $outputStream = $this->outputStream;
+                $this->outputStream = fopen('php://stdout', 'w');
+
+                try {
+                    return parent::supportsColors();
+                } finally {
+                    $this->outputStream = $outputStream;
+                }
+            }
+        };
+
+        return FlattenException::createFromThrowable($exception)
+            ->setAsString($dumper->dump($cloner->cloneVar($exception), true));
+    }
+}
diff --git a/src/Symfony/Component/ErrorHandler/ErrorRenderer/ErrorRendererInterface.php b/src/Symfony/Component/ErrorHandler/ErrorRenderer/ErrorRendererInterface.php
new file mode 100644
index 0000000000000..aba196603fdc9
--- /dev/null
+++ b/src/Symfony/Component/ErrorHandler/ErrorRenderer/ErrorRendererInterface.php
@@ -0,0 +1,27 @@
+<?php
+
+/*
+ * This file is part of the Symfony package.
+ *
+ * (c) Fabien Potencier <fabien@symfony.com>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace Symfony\Component\ErrorHandler\ErrorRenderer;
+
+use Symfony\Component\ErrorHandler\Exception\FlattenException;
+
+/**
+ * Formats an exception to be used as response content.
+ *
+ * @author Yonel Ceruto <yonelceruto@gmail.com>
+ */
+interface ErrorRendererInterface
+{
+    /**
+     * Renders a Throwable as a FlattenException.
+     */
+    public function render(\Throwable $exception): FlattenException;
+}
diff --git a/src/Symfony/Component/ErrorRenderer/ErrorRenderer/HtmlErrorRenderer.php b/src/Symfony/Component/ErrorHandler/ErrorRenderer/HtmlErrorRenderer.php
similarity index 96%
rename from src/Symfony/Component/ErrorRenderer/ErrorRenderer/HtmlErrorRenderer.php
rename to src/Symfony/Component/ErrorHandler/ErrorRenderer/HtmlErrorRenderer.php
index a9d0af516da13..68a9d6bb14dc6 100644
--- a/src/Symfony/Component/ErrorRenderer/ErrorRenderer/HtmlErrorRenderer.php
+++ b/src/Symfony/Component/ErrorHandler/ErrorRenderer/HtmlErrorRenderer.php
@@ -9,10 +9,10 @@
  * file that was distributed with this source code.
  */
 
-namespace Symfony\Component\ErrorRenderer\ErrorRenderer;
+namespace Symfony\Component\ErrorHandler\ErrorRenderer;
 
 use Psr\Log\LoggerInterface;
-use Symfony\Component\ErrorRenderer\Exception\FlattenException;
+use Symfony\Component\ErrorHandler\Exception\FlattenException;
 use Symfony\Component\HttpFoundation\RequestStack;
 use Symfony\Component\HttpFoundation\Response;
 use Symfony\Component\HttpKernel\Log\DebugLoggerInterface;
@@ -52,23 +52,17 @@ public function __construct(bool $debug = false, string $charset = null, $fileLi
     /**
      * {@inheritdoc}
      */
-    public static function getFormat(): string
+    public function render(\Throwable  $exception): FlattenException
     {
-        return 'html';
-    }
-
-    /**
-     * {@inheritdoc}
-     */
-    public function render(FlattenException $exception): string
-    {
-        return $this->renderException($exception);
+        $exception = FlattenException::createFromThrowable($exception, null, [
+            'Content-Type' => 'text/html; charset='.$this->charset,
+        ]);
+        
+        return $exception->setAsString($this->renderException($exception));
     }
 
     /**
      * Gets the HTML content associated with the given exception.
-     *
-     * @internal
      */
     public function getBody(FlattenException $exception): string
     {
@@ -77,8 +71,6 @@ public function getBody(FlattenException $exception): string
 
     /**
      * Gets the stylesheet associated with the given exception.
-     *
-     * @internal
      */
     public function getStylesheet(): string
     {
@@ -91,11 +83,10 @@ public function getStylesheet(): string
 
     private function renderException(FlattenException $exception, string $debugTemplate = 'views/exception_full.html.php'): string
     {
-        $debug = $this->debug && ($exception->getHeaders()['X-Debug'] ?? true);
-        $statusText = $this->escape($exception->getTitle());
+        $statusText = $this->escape($exception->getStatusText());
         $statusCode = $this->escape($exception->getStatusCode());
 
-        if (!$debug) {
+        if (!$this->debug) {
             return $this->include('views/error.html.php', [
                 'statusText' => $statusText,
                 'statusCode' => $statusCode,
@@ -111,7 +102,7 @@ private function renderException(FlattenException $exception, string $debugTempl
             'statusText' => $statusText,
             'statusCode' => $statusCode,
             'logger' => $this->logger instanceof DebugLoggerInterface ? $this->logger : null,
-            'currentContent' => $request ? $this->getAndCleanOutputBuffering($request->headers->get('X-Php-Ob-Level')) : null,
+            'currentContent' => $request ? $this->getAndCleanOutputBuffering($request->headers->get('X-Php-Ob-Level', -1)) : '',
         ]);
     }
 
@@ -321,7 +312,7 @@ private function include(string $name, array $context = []): string
     {
         extract($context, EXTR_SKIP);
         ob_start();
-        include __DIR__.'/../Resources/'.$name;
+        include __DIR__ . '/../Resources/' .$name;
 
         return trim(ob_get_clean());
     }
diff --git a/src/Symfony/Component/ErrorHandler/ErrorRenderer/SerializerErrorRenderer.php b/src/Symfony/Component/ErrorHandler/ErrorRenderer/SerializerErrorRenderer.php
new file mode 100644
index 0000000000000..c055bc3b65db3
--- /dev/null
+++ b/src/Symfony/Component/ErrorHandler/ErrorRenderer/SerializerErrorRenderer.php
@@ -0,0 +1,70 @@
+<?php
+
+/*
+ * This file is part of the Symfony package.
+ *
+ * (c) Fabien Potencier <fabien@symfony.com>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace Symfony\Component\ErrorHandler\ErrorRenderer;
+
+use Symfony\Component\ErrorHandler\Exception\FlattenException;
+use Symfony\Component\HttpFoundation\RequestStack;
+use Symfony\Component\Serializer\Exception\NotEncodableValueException;
+use Symfony\Component\Serializer\SerializerInterface;
+
+/**
+ * Formats an exception using Serializer for rendering.
+ *
+ * @author Nicolas Grekas <p@tchwork.com>
+ */
+class SerializerErrorRenderer implements ErrorRendererInterface
+{
+    private $serializer;
+    private $format;
+    private $fallbackErrorRenderer;
+
+    /**
+     * @param string|callable(FlattenException) $format The format as a string or a callable that should return it
+     */
+    public function __construct(SerializerInterface $serializer, $format, ErrorRendererInterface $fallbackErrorRenderer = null)
+    {
+        if (!\is_string($format) && !\is_callable($format)) {
+            throw new \TypeError(sprintf('Argument 2 passed to %s() must be a string or a callable, %s given.', __METHOD__, \is_object($format) ? \get_class($format) : \gettype($format)));
+        }
+
+        $this->serializer = $serializer;
+        $this->format = $format;
+        $this->fallbackErrorRenderer = $fallbackErrorRenderer ?? new HtmlErrorRenderer();
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function render(\Throwable $exception): FlattenException
+    {
+        $flattenException = FlattenException::createFromThrowable($exception);
+
+        try {
+            $format = \is_string($this->format) ? $this->format : ($this->format)($flattenException);
+
+            return $flattenException->setAsString($this->serializer->serialize($flattenException, $format, ['exception' => $exception]));
+        } catch (NotEncodableValueException $e) {
+            return $this->fallbackErrorRenderer->render($exception);
+        }
+    }
+
+    public static function getPreferredFormat(RequestStack $requestStack): \Closure
+    {
+        return static function () use ($requestStack) {
+            if (!$request = $requestStack->getCurrentRequest()) {
+                throw new NotEncodableValueException();
+            }
+
+            return $request->getPreferredFormat();
+        };
+    }
+}
diff --git a/src/Symfony/Component/ErrorRenderer/Exception/FlattenException.php b/src/Symfony/Component/ErrorHandler/Exception/FlattenException.php
similarity index 93%
rename from src/Symfony/Component/ErrorRenderer/Exception/FlattenException.php
rename to src/Symfony/Component/ErrorHandler/Exception/FlattenException.php
index dd86f5b74bb07..61af8a7e1d8a7 100644
--- a/src/Symfony/Component/ErrorRenderer/Exception/FlattenException.php
+++ b/src/Symfony/Component/ErrorHandler/Exception/FlattenException.php
@@ -9,7 +9,7 @@
  * file that was distributed with this source code.
  */
 
-namespace Symfony\Component\ErrorRenderer\Exception;
+namespace Symfony\Component\ErrorHandler\Exception;
 
 use Symfony\Component\Debug\Exception\FlattenException as LegacyFlattenException;
 use Symfony\Component\HttpFoundation\Exception\RequestExceptionInterface;
@@ -25,7 +25,6 @@
  */
 class FlattenException extends LegacyFlattenException
 {
-    private $title;
     private $message;
     private $code;
     private $previous;
@@ -33,9 +32,11 @@ class FlattenException extends LegacyFlattenException
     private $traceAsString;
     private $class;
     private $statusCode;
+    private $statusText;
     private $headers;
     private $file;
     private $line;
+    private $asString;
 
     public static function create(\Exception $exception, $statusCode = null, array $headers = []): self
     {
@@ -60,12 +61,12 @@ public static function createFromThrowable(\Throwable $exception, int $statusCod
         }
 
         if (class_exists(Response::class) && isset(Response::$statusTexts[$statusCode])) {
-            $title = Response::$statusTexts[$statusCode];
+            $statusText = Response::$statusTexts[$statusCode];
         } else {
-            $title = 'Whoops, looks like something went wrong.';
+            $statusText = 'Whoops, looks like something went wrong.';
         }
 
-        $e->setTitle($title);
+        $e->setStatusText($statusText);
         $e->setStatusCode($statusCode);
         $e->setHeaders($headers);
         $e->setTraceFromThrowable($exception);
@@ -171,14 +172,14 @@ public function setLine($line): self
         return $this;
     }
 
-    public function getTitle()
+    public function getStatusText()
     {
-        return $this->title;
+        return $this->statusText;
     }
 
-    public function setTitle(string $title): self
+    public function setStatusText(string $statusText): self
     {
-        $this->title = $title;
+        $this->statusText = $statusText;
 
         return $this;
     }
@@ -355,8 +356,19 @@ public function getTraceAsString()
         return $this->traceAsString;
     }
 
+    public function setAsString(?string $asString)
+    {
+        $this->asString = $asString;
+
+        return $this;
+    }
+
     public function getAsString()
     {
+        if (null !== $this->asString) {
+            return $this->asString;
+        }
+
         $message = '';
         $next = false;
 
diff --git a/src/Symfony/Component/ErrorRenderer/Resources/assets/css/error.css b/src/Symfony/Component/ErrorHandler/Resources/assets/css/error.css
similarity index 100%
rename from src/Symfony/Component/ErrorRenderer/Resources/assets/css/error.css
rename to src/Symfony/Component/ErrorHandler/Resources/assets/css/error.css
diff --git a/src/Symfony/Component/ErrorRenderer/Resources/assets/css/exception.css b/src/Symfony/Component/ErrorHandler/Resources/assets/css/exception.css
similarity index 100%
rename from src/Symfony/Component/ErrorRenderer/Resources/assets/css/exception.css
rename to src/Symfony/Component/ErrorHandler/Resources/assets/css/exception.css
diff --git a/src/Symfony/Component/ErrorRenderer/Resources/assets/css/exception_full.css b/src/Symfony/Component/ErrorHandler/Resources/assets/css/exception_full.css
similarity index 100%
rename from src/Symfony/Component/ErrorRenderer/Resources/assets/css/exception_full.css
rename to src/Symfony/Component/ErrorHandler/Resources/assets/css/exception_full.css
diff --git a/src/Symfony/Component/ErrorRenderer/Resources/assets/images/chevron-right.svg b/src/Symfony/Component/ErrorHandler/Resources/assets/images/chevron-right.svg
similarity index 100%
rename from src/Symfony/Component/ErrorRenderer/Resources/assets/images/chevron-right.svg
rename to src/Symfony/Component/ErrorHandler/Resources/assets/images/chevron-right.svg
diff --git a/src/Symfony/Component/ErrorRenderer/Resources/assets/images/favicon.png.base64 b/src/Symfony/Component/ErrorHandler/Resources/assets/images/favicon.png.base64
similarity index 100%
rename from src/Symfony/Component/ErrorRenderer/Resources/assets/images/favicon.png.base64
rename to src/Symfony/Component/ErrorHandler/Resources/assets/images/favicon.png.base64
diff --git a/src/Symfony/Component/ErrorRenderer/Resources/assets/images/icon-book.svg b/src/Symfony/Component/ErrorHandler/Resources/assets/images/icon-book.svg
similarity index 100%
rename from src/Symfony/Component/ErrorRenderer/Resources/assets/images/icon-book.svg
rename to src/Symfony/Component/ErrorHandler/Resources/assets/images/icon-book.svg
diff --git a/src/Symfony/Component/ErrorRenderer/Resources/assets/images/icon-minus-square-o.svg b/src/Symfony/Component/ErrorHandler/Resources/assets/images/icon-minus-square-o.svg
similarity index 100%
rename from src/Symfony/Component/ErrorRenderer/Resources/assets/images/icon-minus-square-o.svg
rename to src/Symfony/Component/ErrorHandler/Resources/assets/images/icon-minus-square-o.svg
diff --git a/src/Symfony/Component/ErrorRenderer/Resources/assets/images/icon-minus-square.svg b/src/Symfony/Component/ErrorHandler/Resources/assets/images/icon-minus-square.svg
similarity index 100%
rename from src/Symfony/Component/ErrorRenderer/Resources/assets/images/icon-minus-square.svg
rename to src/Symfony/Component/ErrorHandler/Resources/assets/images/icon-minus-square.svg
diff --git a/src/Symfony/Component/ErrorRenderer/Resources/assets/images/icon-plus-square-o.svg b/src/Symfony/Component/ErrorHandler/Resources/assets/images/icon-plus-square-o.svg
similarity index 100%
rename from src/Symfony/Component/ErrorRenderer/Resources/assets/images/icon-plus-square-o.svg
rename to src/Symfony/Component/ErrorHandler/Resources/assets/images/icon-plus-square-o.svg
diff --git a/src/Symfony/Component/ErrorRenderer/Resources/assets/images/icon-plus-square.svg b/src/Symfony/Component/ErrorHandler/Resources/assets/images/icon-plus-square.svg
similarity index 100%
rename from src/Symfony/Component/ErrorRenderer/Resources/assets/images/icon-plus-square.svg
rename to src/Symfony/Component/ErrorHandler/Resources/assets/images/icon-plus-square.svg
diff --git a/src/Symfony/Component/ErrorRenderer/Resources/assets/images/icon-support.svg b/src/Symfony/Component/ErrorHandler/Resources/assets/images/icon-support.svg
similarity index 100%
rename from src/Symfony/Component/ErrorRenderer/Resources/assets/images/icon-support.svg
rename to src/Symfony/Component/ErrorHandler/Resources/assets/images/icon-support.svg
diff --git a/src/Symfony/Component/ErrorRenderer/Resources/assets/images/symfony-ghost.svg.php b/src/Symfony/Component/ErrorHandler/Resources/assets/images/symfony-ghost.svg.php
similarity index 100%
rename from src/Symfony/Component/ErrorRenderer/Resources/assets/images/symfony-ghost.svg.php
rename to src/Symfony/Component/ErrorHandler/Resources/assets/images/symfony-ghost.svg.php
diff --git a/src/Symfony/Component/ErrorRenderer/Resources/assets/images/symfony-logo.svg b/src/Symfony/Component/ErrorHandler/Resources/assets/images/symfony-logo.svg
similarity index 100%
rename from src/Symfony/Component/ErrorRenderer/Resources/assets/images/symfony-logo.svg
rename to src/Symfony/Component/ErrorHandler/Resources/assets/images/symfony-logo.svg
diff --git a/src/Symfony/Component/ErrorRenderer/Resources/assets/js/exception.js b/src/Symfony/Component/ErrorHandler/Resources/assets/js/exception.js
similarity index 100%
rename from src/Symfony/Component/ErrorRenderer/Resources/assets/js/exception.js
rename to src/Symfony/Component/ErrorHandler/Resources/assets/js/exception.js
diff --git a/src/Symfony/Component/ErrorHandler/Resources/stubs/Debug.php b/src/Symfony/Component/ErrorHandler/Resources/stubs/Debug.php
deleted file mode 100644
index 2a3f8bed79328..0000000000000
--- a/src/Symfony/Component/ErrorHandler/Resources/stubs/Debug.php
+++ /dev/null
@@ -1,25 +0,0 @@
-<?php
-
-/*
- * This file is part of the Symfony package.
- *
- * (c) Fabien Potencier <fabien@symfony.com>
- *
- * For the full copyright and license information, please view the LICENSE
- * file that was distributed with this source code.
- */
-
-namespace Symfony\Component\Debug;
-
-if (!class_exists(Debug::class, false)) {
-    class_alias(\Symfony\Component\ErrorHandler\Debug::class, Debug::class);
-}
-
-if (false) {
-    /**
-     * @deprecated since Symfony 4.4, use Symfony\Component\ErrorHandler\Debug instead.
-     */
-    class Debug extends \Symfony\Component\ErrorHandler\Debug
-    {
-    }
-}
diff --git a/src/Symfony/Component/ErrorRenderer/Resources/views/error.html.php b/src/Symfony/Component/ErrorHandler/Resources/views/error.html.php
similarity index 100%
rename from src/Symfony/Component/ErrorRenderer/Resources/views/error.html.php
rename to src/Symfony/Component/ErrorHandler/Resources/views/error.html.php
diff --git a/src/Symfony/Component/ErrorRenderer/Resources/views/exception.html.php b/src/Symfony/Component/ErrorHandler/Resources/views/exception.html.php
similarity index 100%
rename from src/Symfony/Component/ErrorRenderer/Resources/views/exception.html.php
rename to src/Symfony/Component/ErrorHandler/Resources/views/exception.html.php
diff --git a/src/Symfony/Component/ErrorHandler/Resources/views/exception_full.html.php b/src/Symfony/Component/ErrorHandler/Resources/views/exception_full.html.php
new file mode 100644
index 0000000000000..4d46d59de5ff0
--- /dev/null
+++ b/src/Symfony/Component/ErrorHandler/Resources/views/exception_full.html.php
@@ -0,0 +1,43 @@
+<!-- <?= $_message = sprintf('%s (%d %s)', $exceptionMessage, $statusCode, $statusText); ?> -->
+<!DOCTYPE html>
+<html lang="en">
+    <head>
+        <meta charset="<?= $this->charset; ?>" />
+        <meta name="robots" content="noindex,nofollow" />
+        <meta name="viewport" content="width=device-width,initial-scale=1" />
+        <title><?= $_message; ?></title>
+        <link rel="icon" type="image/png" href="<?= $this->include('assets/images/favicon.png.base64'); ?>">
+        <style><?= $this->include('assets/css/exception.css'); ?></style>
+        <style><?= $this->include('assets/css/exception_full.css'); ?></style>
+    </head>
+    <body>
+        <?php if (class_exists('Symfony\Component\HttpKernel\Kernel')) { ?>
+            <header>
+                <div class="container">
+                    <h1 class="logo"><?= $this->include('assets/images/symfony-logo.svg'); ?> Symfony Exception</h1>
+
+                    <div class="help-link">
+                        <a href="https://symfony.com/doc/<?= Symfony\Component\HttpKernel\Kernel::VERSION; ?>/index.html">
+                            <span class="icon"><?= $this->include('assets/images/icon-book.svg'); ?></span>
+                            <span class="hidden-xs-down">Symfony</span> Docs
+                        </a>
+                    </div>
+
+                    <div class="help-link">
+                        <a href="https://symfony.com/support">
+                            <span class="icon"><?= $this->include('assets/images/icon-support.svg'); ?></span>
+                            <span class="hidden-xs-down">Symfony</span> Support
+                        </a>
+                    </div>
+                </div>
+            </header>
+        <?php } ?>
+
+        <?= $this->include('views/exception.html.php', $context); ?>
+
+        <script>
+            <?= $this->include('assets/js/exception.js'); ?>
+        </script>
+    </body>
+</html>
+<!-- <?= $_message; ?> -->
diff --git a/src/Symfony/Component/ErrorRenderer/Resources/views/logs.html.php b/src/Symfony/Component/ErrorHandler/Resources/views/logs.html.php
similarity index 100%
rename from src/Symfony/Component/ErrorRenderer/Resources/views/logs.html.php
rename to src/Symfony/Component/ErrorHandler/Resources/views/logs.html.php
diff --git a/src/Symfony/Component/ErrorRenderer/Resources/views/trace.html.php b/src/Symfony/Component/ErrorHandler/Resources/views/trace.html.php
similarity index 100%
rename from src/Symfony/Component/ErrorRenderer/Resources/views/trace.html.php
rename to src/Symfony/Component/ErrorHandler/Resources/views/trace.html.php
diff --git a/src/Symfony/Component/ErrorRenderer/Resources/views/traces.html.php b/src/Symfony/Component/ErrorHandler/Resources/views/traces.html.php
similarity index 100%
rename from src/Symfony/Component/ErrorRenderer/Resources/views/traces.html.php
rename to src/Symfony/Component/ErrorHandler/Resources/views/traces.html.php
diff --git a/src/Symfony/Component/ErrorRenderer/Resources/views/traces_text.html.php b/src/Symfony/Component/ErrorHandler/Resources/views/traces_text.html.php
similarity index 100%
rename from src/Symfony/Component/ErrorRenderer/Resources/views/traces_text.html.php
rename to src/Symfony/Component/ErrorHandler/Resources/views/traces_text.html.php
diff --git a/src/Symfony/Component/ErrorHandler/Tests/ErrorHandlerTest.php b/src/Symfony/Component/ErrorHandler/Tests/ErrorHandlerTest.php
index 1c170732e8983..907294cd770b8 100644
--- a/src/Symfony/Component/ErrorHandler/Tests/ErrorHandlerTest.php
+++ b/src/Symfony/Component/ErrorHandler/Tests/ErrorHandlerTest.php
@@ -50,23 +50,13 @@ public function testRegister()
                 $h = set_error_handler('var_dump');
                 restore_error_handler();
                 $this->assertSame([$newHandler, 'handleError'], $h);
-            } catch (\Exception $e) {
+            } finally {
+                restore_error_handler();
+                restore_exception_handler();
             }
-
+        } finally {
             restore_error_handler();
             restore_exception_handler();
-
-            if (isset($e)) {
-                throw $e;
-            }
-        } catch (\Exception $e) {
-        }
-
-        restore_error_handler();
-        restore_exception_handler();
-
-        if (isset($e)) {
-            throw $e;
         }
     }
 
@@ -86,11 +76,9 @@ public function testErrorGetLast()
                 'line' => __LINE__ - 5,
             ];
             $this->assertSame($expected, error_get_last());
-        } catch (\Exception $e) {
+        } finally {
             restore_error_handler();
             restore_exception_handler();
-
-            throw $e;
         }
     }
 
@@ -323,14 +311,9 @@ public function testHandleError()
             unset($undefVar);
             $line = __LINE__ + 1;
             @$undefVar++;
-
-            restore_error_handler();
-            restore_exception_handler();
-        } catch (\Exception $e) {
+        } finally {
             restore_error_handler();
             restore_exception_handler();
-
-            throw $e;
         }
     }
 
@@ -406,6 +389,7 @@ public function testHandleException(string $expectedMessage, \Throwable $excepti
             ;
 
             $handler->setDefaultLogger($logger, E_ERROR);
+            $handler->setExceptionHandler(null);
 
             try {
                 $handler->handleException($exception);
@@ -530,16 +514,12 @@ public function testHandleFatalError()
             ;
 
             $handler->setDefaultLogger($logger, E_PARSE);
+            $handler->setExceptionHandler(null);
 
             $handler->handleFatalError($error);
-
-            restore_error_handler();
-            restore_exception_handler();
-        } catch (\Exception $e) {
+        } finally {
             restore_error_handler();
             restore_exception_handler();
-
-            throw $e;
         }
     }
 
@@ -563,6 +543,7 @@ public function testCustomExceptionHandler()
         $this->expectException('Exception');
         $handler = new ErrorHandler();
         $handler->setExceptionHandler(function ($e) use ($handler) {
+            $handler->setExceptionHandler(null);
             $handler->handleException($e);
         });
 
@@ -572,7 +553,7 @@ public function testCustomExceptionHandler()
     public function testSendPhpResponse()
     {
         $handler = new ErrorHandler();
-        $handler->setExceptionHandler([$handler, 'sendPhpResponse']);
+        $handler->setExceptionHandler([$handler, 'renderException']);
 
         ob_start();
         $handler->handleException(new \RuntimeException('Class Foo not found'));
diff --git a/src/Symfony/Component/ErrorRenderer/Tests/ErrorRenderer/HtmlErrorRendererTest.php b/src/Symfony/Component/ErrorHandler/Tests/ErrorRenderer/HtmlErrorRendererTest.php
similarity index 51%
rename from src/Symfony/Component/ErrorRenderer/Tests/ErrorRenderer/HtmlErrorRendererTest.php
rename to src/Symfony/Component/ErrorHandler/Tests/ErrorRenderer/HtmlErrorRendererTest.php
index 4868d215c47ce..b140ca6e52f74 100644
--- a/src/Symfony/Component/ErrorRenderer/Tests/ErrorRenderer/HtmlErrorRendererTest.php
+++ b/src/Symfony/Component/ErrorHandler/Tests/ErrorRenderer/HtmlErrorRendererTest.php
@@ -9,21 +9,20 @@
  * file that was distributed with this source code.
  */
 
-namespace Symfony\Component\ErrorRenderer\Tests\ErrorRenderer;
+namespace Symfony\Component\ErrorHandler\Tests\ErrorRenderer;
 
 use PHPUnit\Framework\TestCase;
-use Symfony\Component\ErrorRenderer\ErrorRenderer\ErrorRendererInterface;
-use Symfony\Component\ErrorRenderer\ErrorRenderer\HtmlErrorRenderer;
-use Symfony\Component\ErrorRenderer\Exception\FlattenException;
+use Symfony\Component\ErrorHandler\ErrorRenderer\HtmlErrorRenderer;
+use Symfony\Component\ErrorHandler\Exception\FlattenException;
 
 class HtmlErrorRendererTest extends TestCase
 {
     /**
      * @dataProvider getRenderData
      */
-    public function testRender(FlattenException $exception, ErrorRendererInterface $errorRenderer, string $expected)
+    public function testRender(\Throwable $exception, HtmlErrorRenderer $errorRenderer, string $expected)
     {
-        $this->assertStringMatchesFormat($expected, $errorRenderer->render($exception));
+        $this->assertStringMatchesFormat($expected, $errorRenderer->render($exception)->getAsString());
     }
 
     public function getRenderData(): iterable
@@ -45,25 +44,13 @@ public function getRenderData(): iterable
 HTML;
 
         yield '->render() returns the HTML content WITH stack traces in debug mode' => [
-            FlattenException::createFromThrowable(new \RuntimeException('Foo')),
+            new \RuntimeException('Foo'),
             new HtmlErrorRenderer(true),
             $expectedDebug,
         ];
 
         yield '->render() returns the HTML content WITHOUT stack traces in non-debug mode' => [
-            FlattenException::createFromThrowable(new \RuntimeException('Foo')),
-            new HtmlErrorRenderer(false),
-            $expectedNonDebug,
-        ];
-
-        yield '->render() returns the HTML content WITHOUT stack traces in debug mode FORCING non-debug via X-Debug header' => [
-            FlattenException::createFromThrowable(new \RuntimeException('Foo'), null, ['X-Debug' => false]),
-            new HtmlErrorRenderer(true),
-            $expectedNonDebug,
-        ];
-
-        yield '->render() returns the HTML content WITHOUT stack traces in non-debug mode EVEN FORCING debug via X-Debug header' => [
-            FlattenException::createFromThrowable(new \RuntimeException('Foo'), null, ['X-Debug' => true]),
+            new \RuntimeException('Foo'),
             new HtmlErrorRenderer(false),
             $expectedNonDebug,
         ];
diff --git a/src/Symfony/Component/ErrorHandler/Tests/ErrorRenderer/SerializerErrorRendererTest.php b/src/Symfony/Component/ErrorHandler/Tests/ErrorRenderer/SerializerErrorRendererTest.php
new file mode 100644
index 0000000000000..a1698e0a88cd9
--- /dev/null
+++ b/src/Symfony/Component/ErrorHandler/Tests/ErrorRenderer/SerializerErrorRendererTest.php
@@ -0,0 +1,40 @@
+<?php
+
+/*
+ * This file is part of the Symfony package.
+ *
+ * (c) Fabien Potencier <fabien@symfony.com>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace Symfony\Component\ErrorHandler\Tests\ErrorRenderer;
+
+use PHPUnit\Framework\TestCase;
+use Symfony\Component\ErrorHandler\ErrorRenderer\SerializerErrorRenderer;
+use Symfony\Component\ErrorHandler\Exception\FlattenException;
+use Symfony\Component\Serializer\Encoder\JsonEncoder;
+use Symfony\Component\Serializer\Normalizer\ProblemNormalizer;
+use Symfony\Component\Serializer\Serializer;
+
+class SerializerErrorRendererTest extends TestCase
+{
+    public function testDefaultContent()
+    {
+        $errorRenderer = new SerializerErrorRenderer(new Serializer(), 'html');
+
+        self::assertStringContainsString('<h2>The server returned a "500 Internal Server Error".</h2>', $errorRenderer->render(new \RuntimeException())->getAsString());
+    }
+
+    public function testSerializerContent()
+    {
+        $exception = new \RuntimeException('Foo');
+        $errorRenderer = new SerializerErrorRenderer(
+            new Serializer([new ProblemNormalizer()], [new JsonEncoder()]),
+            function () { return 'json'; }
+        );
+
+        $this->assertSame('{"type":"https:\/\/tools.ietf.org\/html\/rfc2616#section-10","title":"An error occurred","status":500,"detail":"Internal Server Error"}', $errorRenderer->render($exception)->getAsString());
+    }
+}
diff --git a/src/Symfony/Component/ErrorRenderer/Tests/Exception/FlattenExceptionTest.php b/src/Symfony/Component/ErrorHandler/Tests/Exception/FlattenExceptionTest.php
similarity index 99%
rename from src/Symfony/Component/ErrorRenderer/Tests/Exception/FlattenExceptionTest.php
rename to src/Symfony/Component/ErrorHandler/Tests/Exception/FlattenExceptionTest.php
index dad78d152540d..3413bd484e04c 100644
--- a/src/Symfony/Component/ErrorRenderer/Tests/Exception/FlattenExceptionTest.php
+++ b/src/Symfony/Component/ErrorHandler/Tests/Exception/FlattenExceptionTest.php
@@ -9,10 +9,10 @@
  * file that was distributed with this source code.
  */
 
-namespace Symfony\Component\ErrorRenderer\Tests\Exception;
+namespace Symfony\Component\ErrorHandler\Tests\Exception;
 
 use PHPUnit\Framework\TestCase;
-use Symfony\Component\ErrorRenderer\Exception\FlattenException;
+use Symfony\Component\ErrorHandler\Exception\FlattenException;
 use Symfony\Component\HttpFoundation\Exception\SuspiciousOperationException;
 use Symfony\Component\HttpKernel\Exception\AccessDeniedHttpException;
 use Symfony\Component\HttpKernel\Exception\BadRequestHttpException;
diff --git a/src/Symfony/Component/ErrorHandler/Tests/phpt/exception_rethrown.phpt b/src/Symfony/Component/ErrorHandler/Tests/phpt/exception_rethrown.phpt
index 82a9006d840f9..8e6c5222d03f6 100644
--- a/src/Symfony/Component/ErrorHandler/Tests/phpt/exception_rethrown.phpt
+++ b/src/Symfony/Component/ErrorHandler/Tests/phpt/exception_rethrown.phpt
@@ -16,20 +16,23 @@ if (true) {
     {
         public function log($level, $message, array $context = [])
         {
-            echo $message, "\n";
+            echo 'LOG: ', $message, "\n";
         }
     }
 }
 
-set_exception_handler(function ($e) { echo 123; throw $e; });
+$_SERVER['NO_COLOR'] = '1';
+set_exception_handler(function ($e) { echo "EHLO\n"; throw $e; });
 ErrorHandler::register()->setDefaultLogger(new TestLogger());
-ini_set('display_errors', 1);
 
 throw new \Exception('foo');
 ?>
 --EXPECTF--
-Uncaught Exception: foo
-123
-Fatal error: Uncaught %s:25
-Stack trace:
-%a
+LOG: Uncaught Exception: foo
+EHLO
+Exception {%S
+  #message: "foo"
+  #code: 0
+  #file: "%s"
+  #line: 25
+}
diff --git a/src/Symfony/Component/ErrorHandler/composer.json b/src/Symfony/Component/ErrorHandler/composer.json
index dd5e0d0679111..cfe822f4e8b39 100644
--- a/src/Symfony/Component/ErrorHandler/composer.json
+++ b/src/Symfony/Component/ErrorHandler/composer.json
@@ -17,20 +17,16 @@
     ],
     "require": {
         "php": "^7.1.3",
-        "psr/log": "~1.0"
+        "psr/log": "~1.0",
+        "symfony/debug": "^4.4",
+        "symfony/var-dumper": "^4.4|^5.0"
     },
     "require-dev": {
-        "symfony/http-kernel": "^3.4|^4.0|^5.0"
-    },
-    "suggest": {
-        "symfony/error-renderer": "For better error rendering"
-    },
-    "conflict": {
-        "symfony/http-kernel": "<3.4"
+        "symfony/http-kernel": "^4.4|^5.0",
+        "symfony/serializer": "^4.4|^5.0"
     },
     "autoload": {
         "psr-4": { "Symfony\\Component\\ErrorHandler\\": "" },
-        "classmap": [ "Resources/stubs/Debug.php" ],
         "exclude-from-classmap": [
             "/Tests/"
         ]
diff --git a/src/Symfony/Component/ErrorRenderer/.gitattributes b/src/Symfony/Component/ErrorRenderer/.gitattributes
deleted file mode 100644
index ebb9287043dc4..0000000000000
--- a/src/Symfony/Component/ErrorRenderer/.gitattributes
+++ /dev/null
@@ -1,3 +0,0 @@
-/Tests export-ignore
-/phpunit.xml.dist export-ignore
-/.gitignore export-ignore
diff --git a/src/Symfony/Component/ErrorRenderer/.gitignore b/src/Symfony/Component/ErrorRenderer/.gitignore
deleted file mode 100644
index c49a5d8df5c65..0000000000000
--- a/src/Symfony/Component/ErrorRenderer/.gitignore
+++ /dev/null
@@ -1,3 +0,0 @@
-vendor/
-composer.lock
-phpunit.xml
diff --git a/src/Symfony/Component/ErrorRenderer/CHANGELOG.md b/src/Symfony/Component/ErrorRenderer/CHANGELOG.md
deleted file mode 100644
index 094072510d707..0000000000000
--- a/src/Symfony/Component/ErrorRenderer/CHANGELOG.md
+++ /dev/null
@@ -1,7 +0,0 @@
-CHANGELOG
-=========
-
-4.4.0
------
-
- * added the component
diff --git a/src/Symfony/Component/ErrorRenderer/Command/DebugCommand.php b/src/Symfony/Component/ErrorRenderer/Command/DebugCommand.php
deleted file mode 100644
index 58cb57b68cbf5..0000000000000
--- a/src/Symfony/Component/ErrorRenderer/Command/DebugCommand.php
+++ /dev/null
@@ -1,125 +0,0 @@
-<?php
-
-/*
- * This file is part of the Symfony package.
- *
- * (c) Fabien Potencier <fabien@symfony.com>
- *
- * For the full copyright and license information, please view the LICENSE
- * file that was distributed with this source code.
- */
-
-namespace Symfony\Component\ErrorRenderer\Command;
-
-use Symfony\Component\Console\Command\Command;
-use Symfony\Component\Console\Exception\InvalidArgumentException;
-use Symfony\Component\Console\Input\InputArgument;
-use Symfony\Component\Console\Input\InputInterface;
-use Symfony\Component\Console\Output\OutputInterface;
-use Symfony\Component\Console\Style\SymfonyStyle;
-use Symfony\Component\ErrorRenderer\ErrorRenderer\ErrorRendererInterface;
-use Symfony\Component\ErrorRenderer\Exception\FlattenException;
-use Symfony\Component\HttpKernel\Debug\FileLinkFormatter;
-
-/**
- * A console command for retrieving information about error renderers.
- *
- * @author Yonel Ceruto <yonelceruto@gmail.com>
- *
- * @internal
- */
-class DebugCommand extends Command
-{
-    protected static $defaultName = 'debug:error-renderer';
-
-    private $renderers;
-    private $fileLinkFormatter;
-
-    /**
-     * @param ErrorRendererInterface[] $renderers
-     */
-    public function __construct(array $renderers, FileLinkFormatter $fileLinkFormatter = null)
-    {
-        $this->renderers = $renderers;
-        $this->fileLinkFormatter = $fileLinkFormatter;
-
-        parent::__construct();
-    }
-
-    /**
-     * {@inheritdoc}
-     */
-    protected function configure(): void
-    {
-        $this
-            ->addArgument('format', InputArgument::OPTIONAL, sprintf('Outputs a sample in a specific format (one of %s)', implode(', ', array_keys($this->renderers))))
-            ->setDescription('Displays all available error renderers and their formats.')
-            ->setHelp(<<<'EOF'
-The <info>%command.name%</info> command displays all available error renderers and
-their formats:
-
-  <info>php %command.full_name%</info>
-
-Or output a sample in a specific format:
-
-  <info>php %command.full_name% json</info>
-
-EOF
-            )
-        ;
-    }
-
-    /**
-     * {@inheritdoc}
-     */
-    protected function execute(InputInterface $input, OutputInterface $output)
-    {
-        $io = new SymfonyStyle($input, $output);
-        $renderers = $this->renderers;
-
-        if ($format = $input->getArgument('format')) {
-            if (!isset($renderers[$format])) {
-                throw new InvalidArgumentException(sprintf('No error renderer found for format "%s". Known format are %s.', $format, implode(', ', array_keys($this->renderers))));
-            }
-
-            $exception = FlattenException::createFromThrowable(new \Exception('This is a sample exception.'), 500, ['X-Debug' => false]);
-            $io->writeln($renderers[$format]->render($exception));
-        } else {
-            $tableRows = [];
-            foreach ($renderers as $format => $renderer) {
-                $tableRows[] = [sprintf('<fg=cyan>%s</fg=cyan>', $format), $this->formatClassLink(\get_class($renderer))];
-            }
-
-            $io->title('Error Renderers');
-            $io->text('The following error renderers are available:');
-            $io->newLine();
-            $io->table(['Format', 'Class'], $tableRows);
-        }
-
-        return 0;
-    }
-
-    private function formatClassLink(string $class): string
-    {
-        if ('' === $fileLink = $this->getFileLink($class)) {
-            return $class;
-        }
-
-        return sprintf('<href=%s>%s</>', $fileLink, $class);
-    }
-
-    private function getFileLink(string $class): string
-    {
-        if (null === $this->fileLinkFormatter) {
-            return '';
-        }
-
-        try {
-            $r = new \ReflectionClass($class);
-        } catch (\ReflectionException $e) {
-            return '';
-        }
-
-        return $this->fileLinkFormatter->format($r->getFileName(), $r->getStartLine());
-    }
-}
diff --git a/src/Symfony/Component/ErrorRenderer/DependencyInjection/ErrorRendererPass.php b/src/Symfony/Component/ErrorRenderer/DependencyInjection/ErrorRendererPass.php
deleted file mode 100644
index 1e297b7de13b3..0000000000000
--- a/src/Symfony/Component/ErrorRenderer/DependencyInjection/ErrorRendererPass.php
+++ /dev/null
@@ -1,71 +0,0 @@
-<?php
-
-/*
- * This file is part of the Symfony package.
- *
- * (c) Fabien Potencier <fabien@symfony.com>
- *
- * For the full copyright and license information, please view the LICENSE
- * file that was distributed with this source code.
- */
-
-namespace Symfony\Component\ErrorRenderer\DependencyInjection;
-
-use Symfony\Component\DependencyInjection\Compiler\CompilerPassInterface;
-use Symfony\Component\DependencyInjection\Compiler\ServiceLocatorTagPass;
-use Symfony\Component\DependencyInjection\ContainerBuilder;
-use Symfony\Component\DependencyInjection\Reference;
-use Symfony\Component\ErrorRenderer\ErrorRenderer\ErrorRendererInterface;
-
-/**
- * @author Yonel Ceruto <yonelceruto@gmail.com>
- */
-class ErrorRendererPass implements CompilerPassInterface
-{
-    private $rendererService;
-    private $rendererTag;
-    private $debugCommandService;
-
-    public function __construct(string $rendererService = 'error_renderer', string $rendererTag = 'error_renderer.renderer', string $debugCommandService = 'console.command.error_renderer_debug')
-    {
-        $this->rendererService = $rendererService;
-        $this->rendererTag = $rendererTag;
-        $this->debugCommandService = $debugCommandService;
-    }
-
-    /**
-     * {@inheritdoc}
-     */
-    public function process(ContainerBuilder $container)
-    {
-        if (!$container->hasDefinition($this->rendererService)) {
-            return;
-        }
-
-        $renderers = [];
-        foreach ($container->findTaggedServiceIds($this->rendererTag, true) as $serviceId => $tags) {
-            /** @var ErrorRendererInterface $class */
-            $class = $container->getDefinition($serviceId)->getClass();
-
-            foreach ($tags as $tag) {
-                $format = $tag['format'] ?? $class::getFormat();
-                $priority = $tag['priority'] ?? 0;
-                if (!isset($renderers[$priority][$format])) {
-                    $renderers[$priority][$format] = new Reference($serviceId);
-                }
-            }
-        }
-
-        if ($renderers) {
-            ksort($renderers);
-            $renderers = array_merge(...$renderers);
-        }
-
-        $definition = $container->getDefinition($this->rendererService);
-        $definition->replaceArgument(0, ServiceLocatorTagPass::register($container, $renderers));
-
-        if ($container->hasDefinition($this->debugCommandService)) {
-            $container->getDefinition($this->debugCommandService)->replaceArgument(0, $renderers);
-        }
-    }
-}
diff --git a/src/Symfony/Component/ErrorRenderer/DependencyInjection/LazyLoadingErrorRenderer.php b/src/Symfony/Component/ErrorRenderer/DependencyInjection/LazyLoadingErrorRenderer.php
deleted file mode 100644
index 82936a29af099..0000000000000
--- a/src/Symfony/Component/ErrorRenderer/DependencyInjection/LazyLoadingErrorRenderer.php
+++ /dev/null
@@ -1,44 +0,0 @@
-<?php
-
-/*
- * This file is part of the Symfony package.
- *
- * (c) Fabien Potencier <fabien@symfony.com>
- *
- * For the full copyright and license information, please view the LICENSE
- * file that was distributed with this source code.
- */
-
-namespace Symfony\Component\ErrorRenderer\DependencyInjection;
-
-use Psr\Container\ContainerInterface;
-use Symfony\Component\ErrorRenderer\ErrorRenderer;
-
-/**
- * Lazily loads error renderers from the dependency injection container.
- *
- * @author Yonel Ceruto <yonelceruto@gmail.com>
- */
-class LazyLoadingErrorRenderer extends ErrorRenderer
-{
-    private $container;
-    private $initialized = [];
-
-    public function __construct(ContainerInterface $container)
-    {
-        $this->container = $container;
-    }
-
-    /**
-     * {@inheritdoc}
-     */
-    public function render($exception, string $format = 'html'): string
-    {
-        if (!isset($this->initialized[$format]) && $this->container->has($format)) {
-            $this->addRenderer($this->container->get($format), $format);
-            $this->initialized[$format] = true;
-        }
-
-        return parent::render($exception, $format);
-    }
-}
diff --git a/src/Symfony/Component/ErrorRenderer/ErrorRenderer.php b/src/Symfony/Component/ErrorRenderer/ErrorRenderer.php
deleted file mode 100644
index da984bdd18895..0000000000000
--- a/src/Symfony/Component/ErrorRenderer/ErrorRenderer.php
+++ /dev/null
@@ -1,77 +0,0 @@
-<?php
-
-/*
- * This file is part of the Symfony package.
- *
- * (c) Fabien Potencier <fabien@symfony.com>
- *
- * For the full copyright and license information, please view the LICENSE
- * file that was distributed with this source code.
- */
-
-namespace Symfony\Component\ErrorRenderer;
-
-use Symfony\Component\ErrorRenderer\ErrorRenderer\ErrorRendererInterface;
-use Symfony\Component\ErrorRenderer\Exception\ErrorRendererNotFoundException;
-use Symfony\Component\ErrorRenderer\Exception\FlattenException;
-
-/**
- * Formats an exception to be used as response content.
- *
- * It delegates to implementations of ErrorRendererInterface depending on the format.
- *
- * @see ErrorRendererInterface
- *
- * @author Yonel Ceruto <yonelceruto@gmail.com>
- */
-class ErrorRenderer
-{
-    private $renderers = [];
-
-    /**
-     * @param ErrorRendererInterface[] $renderers
-     */
-    public function __construct(iterable $renderers)
-    {
-        foreach ($renderers as $renderer) {
-            $this->addRenderer($renderer);
-        }
-    }
-
-    /**
-     * Registers an error renderer that is format specific.
-     *
-     * By passing an explicit format you can register a renderer for a different format than what
-     * ErrorRendererInterface::getFormat() would return in order to register the same renderer for
-     * several format aliases.
-     */
-    public function addRenderer(ErrorRendererInterface $renderer, string $format = null): self
-    {
-        $this->renderers[$format ?? $renderer::getFormat()] = $renderer;
-
-        return $this;
-    }
-
-    /**
-     * Renders an Exception and returns the Response content.
-     *
-     * @param \Throwable|FlattenException $exception A \Throwable or FlattenException instance
-     * @param string                      $format    The request format (html, json, xml, etc.)
-     *
-     * @return string The Response content as a string
-     *
-     * @throws ErrorRendererNotFoundException if no renderer is found
-     */
-    public function render($exception, string $format = 'html'): string
-    {
-        if (!isset($this->renderers[$format])) {
-            throw new ErrorRendererNotFoundException(sprintf('No error renderer found for format "%s".', $format));
-        }
-
-        if ($exception instanceof \Throwable) {
-            $exception = FlattenException::createFromThrowable($exception);
-        }
-
-        return $this->renderers[$format]->render($exception);
-    }
-}
diff --git a/src/Symfony/Component/ErrorRenderer/ErrorRenderer/ErrorRendererInterface.php b/src/Symfony/Component/ErrorRenderer/ErrorRenderer/ErrorRendererInterface.php
deleted file mode 100644
index 5c0d58060202d..0000000000000
--- a/src/Symfony/Component/ErrorRenderer/ErrorRenderer/ErrorRendererInterface.php
+++ /dev/null
@@ -1,32 +0,0 @@
-<?php
-
-/*
- * This file is part of the Symfony package.
- *
- * (c) Fabien Potencier <fabien@symfony.com>
- *
- * For the full copyright and license information, please view the LICENSE
- * file that was distributed with this source code.
- */
-
-namespace Symfony\Component\ErrorRenderer\ErrorRenderer;
-
-use Symfony\Component\ErrorRenderer\Exception\FlattenException;
-
-/**
- * Interface for classes that can render errors in a specific format.
- *
- * @author Yonel Ceruto <yonelceruto@gmail.com>
- */
-interface ErrorRendererInterface
-{
-    /**
-     * Gets the format this renderer can return errors as.
-     */
-    public static function getFormat(): string;
-
-    /**
-     * Returns the response content of the rendered exception.
-     */
-    public function render(FlattenException $exception): string;
-}
diff --git a/src/Symfony/Component/ErrorRenderer/ErrorRenderer/JsonErrorRenderer.php b/src/Symfony/Component/ErrorRenderer/ErrorRenderer/JsonErrorRenderer.php
deleted file mode 100644
index d708fb0f15c85..0000000000000
--- a/src/Symfony/Component/ErrorRenderer/ErrorRenderer/JsonErrorRenderer.php
+++ /dev/null
@@ -1,60 +0,0 @@
-<?php
-
-/*
- * This file is part of the Symfony package.
- *
- * (c) Fabien Potencier <fabien@symfony.com>
- *
- * For the full copyright and license information, please view the LICENSE
- * file that was distributed with this source code.
- */
-
-namespace Symfony\Component\ErrorRenderer\ErrorRenderer;
-
-use Symfony\Component\ErrorRenderer\Exception\FlattenException;
-
-/**
- * @author Yonel Ceruto <yonelceruto@gmail.com>
- */
-class JsonErrorRenderer implements ErrorRendererInterface
-{
-    private $debug;
-
-    public function __construct(bool $debug = false)
-    {
-        $this->debug = $debug;
-    }
-
-    /**
-     * {@inheritdoc}
-     */
-    public static function getFormat(): string
-    {
-        return 'json';
-    }
-
-    /**
-     * {@inheritdoc}
-     */
-    public function render(FlattenException $exception): string
-    {
-        $debug = $this->debug && ($exception->getHeaders()['X-Debug'] ?? true);
-
-        if ($debug) {
-            $message = $exception->getMessage();
-        } else {
-            $message = 404 === $exception->getStatusCode() ? 'Sorry, the page you are looking for could not be found.' : 'Whoops, looks like something went wrong.';
-        }
-
-        $content = [
-            'title' => $exception->getTitle(),
-            'status' => $exception->getStatusCode(),
-            'detail' => $message,
-        ];
-        if ($debug) {
-            $content['exceptions'] = $exception->toArray();
-        }
-
-        return (string) json_encode($content, JSON_PRETTY_PRINT | JSON_UNESCAPED_UNICODE | JSON_UNESCAPED_SLASHES | JSON_UNESCAPED_LINE_TERMINATORS | JSON_PRESERVE_ZERO_FRACTION);
-    }
-}
diff --git a/src/Symfony/Component/ErrorRenderer/ErrorRenderer/TxtErrorRenderer.php b/src/Symfony/Component/ErrorRenderer/ErrorRenderer/TxtErrorRenderer.php
deleted file mode 100644
index 2bafb2cfb4d8b..0000000000000
--- a/src/Symfony/Component/ErrorRenderer/ErrorRenderer/TxtErrorRenderer.php
+++ /dev/null
@@ -1,104 +0,0 @@
-<?php
-
-/*
- * This file is part of the Symfony package.
- *
- * (c) Fabien Potencier <fabien@symfony.com>
- *
- * For the full copyright and license information, please view the LICENSE
- * file that was distributed with this source code.
- */
-
-namespace Symfony\Component\ErrorRenderer\ErrorRenderer;
-
-use Symfony\Component\ErrorRenderer\Exception\FlattenException;
-
-/**
- * @author Yonel Ceruto <yonelceruto@gmail.com>
- */
-class TxtErrorRenderer implements ErrorRendererInterface
-{
-    private $debug;
-
-    public function __construct(bool $debug = false)
-    {
-        $this->debug = $debug;
-    }
-
-    /**
-     * {@inheritdoc}
-     */
-    public static function getFormat(): string
-    {
-        return 'txt';
-    }
-
-    /**
-     * {@inheritdoc}
-     */
-    public function render(FlattenException $exception): string
-    {
-        $debug = $this->debug && ($exception->getHeaders()['X-Debug'] ?? true);
-
-        if ($debug) {
-            $message = $exception->getMessage();
-        } else {
-            $message = 404 === $exception->getStatusCode() ? 'Sorry, the page you are looking for could not be found.' : 'Whoops, looks like something went wrong.';
-        }
-
-        $content = sprintf("[title] %s\n", $exception->getTitle());
-        $content .= sprintf("[status] %s\n", $exception->getStatusCode());
-        $content .= sprintf("[detail] %s\n", $message);
-
-        if ($debug) {
-            foreach ($exception->toArray() as $i => $e) {
-                $content .= sprintf("[%d] %s: %s\n", $i + 1, $e['class'], $e['message']);
-                foreach ($e['trace'] as $trace) {
-                    if ($trace['function']) {
-                        $content .= sprintf('at %s%s%s(%s) ', $trace['class'], $trace['type'], $trace['function'], $this->formatArgs($trace['args']));
-                    }
-                    if (isset($trace['file'], $trace['line'])) {
-                        $content .= $this->formatPath($trace['file'], $trace['line']);
-                    }
-                    $content .= "\n";
-                }
-            }
-        }
-
-        return $content;
-    }
-
-    private function formatPath(string $path, int $line): string
-    {
-        $file = preg_match('#[^/\\\\]*+$#', $path, $file) ? $file[0] : $path;
-
-        return sprintf('in %s %s', $path, 0 < $line ? ' line '.$line : '');
-    }
-
-    /**
-     * Formats an array as a string.
-     */
-    private function formatArgs(array $args): string
-    {
-        $result = [];
-        foreach ($args as $key => $item) {
-            if ('object' === $item[0]) {
-                $formattedValue = sprintf('object(%s)', $item[1]);
-            } elseif ('array' === $item[0]) {
-                $formattedValue = sprintf('array(%s)', \is_array($item[1]) ? $this->formatArgs($item[1]) : $item[1]);
-            } elseif ('null' === $item[0]) {
-                $formattedValue = 'null';
-            } elseif ('boolean' === $item[0]) {
-                $formattedValue = strtolower(var_export($item[1], true));
-            } elseif ('resource' === $item[0]) {
-                $formattedValue = 'resource';
-            } else {
-                $formattedValue = str_replace("\n", '', var_export($item[1], true));
-            }
-
-            $result[] = \is_int($key) ? $formattedValue : sprintf("'%s' => %s", $key, $formattedValue);
-        }
-
-        return implode(', ', $result);
-    }
-}
diff --git a/src/Symfony/Component/ErrorRenderer/ErrorRenderer/XmlErrorRenderer.php b/src/Symfony/Component/ErrorRenderer/ErrorRenderer/XmlErrorRenderer.php
deleted file mode 100644
index 290e0a63ffef1..0000000000000
--- a/src/Symfony/Component/ErrorRenderer/ErrorRenderer/XmlErrorRenderer.php
+++ /dev/null
@@ -1,125 +0,0 @@
-<?php
-
-/*
- * This file is part of the Symfony package.
- *
- * (c) Fabien Potencier <fabien@symfony.com>
- *
- * For the full copyright and license information, please view the LICENSE
- * file that was distributed with this source code.
- */
-
-namespace Symfony\Component\ErrorRenderer\ErrorRenderer;
-
-use Symfony\Component\ErrorRenderer\Exception\FlattenException;
-
-/**
- * @author Yonel Ceruto <yonelceruto@gmail.com>
- */
-class XmlErrorRenderer implements ErrorRendererInterface
-{
-    private $debug;
-    private $charset;
-
-    public function __construct(bool $debug = false, string $charset = null)
-    {
-        $this->debug = $debug;
-        $this->charset = $charset ?: (ini_get('default_charset') ?: 'UTF-8');
-    }
-
-    /**
-     * {@inheritdoc}
-     */
-    public static function getFormat(): string
-    {
-        return 'xml';
-    }
-
-    /**
-     * {@inheritdoc}
-     */
-    public function render(FlattenException $exception): string
-    {
-        $debug = $this->debug && ($exception->getHeaders()['X-Debug'] ?? true);
-        $title = $this->escapeXml($exception->getTitle());
-        if ($debug) {
-            $message = $this->escapeXml($exception->getMessage());
-        } else {
-            $message = 404 === $exception->getStatusCode() ? 'Sorry, the page you are looking for could not be found.' : 'Whoops, looks like something went wrong.';
-        }
-        $statusCode = $this->escapeXml($exception->getStatusCode());
-        $charset = $this->escapeXml($this->charset);
-
-        $exceptions = '';
-        if ($debug) {
-            $exceptions .= '<exceptions>';
-            foreach ($exception->toArray() as $e) {
-                $exceptions .= sprintf('<exception class="%s" message="%s"><traces>', $e['class'], $this->escapeXml($e['message']));
-                foreach ($e['trace'] as $trace) {
-                    $exceptions .= '<trace>';
-                    if ($trace['function']) {
-                        $exceptions .= sprintf('at %s%s%s(%s) ', $trace['class'], $trace['type'], $trace['function'], $this->formatArgs($trace['args']));
-                    }
-                    if (isset($trace['file'], $trace['line'])) {
-                        $exceptions .= $this->formatPath($trace['file'], $trace['line']);
-                    }
-                    $exceptions .= '</trace>';
-                }
-                $exceptions .= '</traces></exception>';
-            }
-            $exceptions .= '</exceptions>';
-        }
-
-        return <<<EOF
-<?xml version="1.0" encoding="{$charset}" ?>
-<problem xmlns="urn:ietf:rfc:7807">
-    <title>{$title}</title>
-    <status>{$statusCode}</status>
-    <detail>{$message}</detail>
-    {$exceptions}
-</problem>
-EOF;
-    }
-
-    /**
-     * XML-encodes a string.
-     */
-    private function escapeXml(string $str): string
-    {
-        return htmlspecialchars($str, ENT_COMPAT | ENT_SUBSTITUTE, $this->charset);
-    }
-
-    private function formatPath(string $path, int $line): string
-    {
-        $file = $this->escapeXml(preg_match('#[^/\\\\]*+$#', $path, $file) ? $file[0] : $path);
-
-        return sprintf('in %s %s', $this->escapeXml($path), 0 < $line ? ' line '.$line : '');
-    }
-
-    /**
-     * Formats an array as a string.
-     */
-    private function formatArgs(array $args): string
-    {
-        $result = [];
-        foreach ($args as $key => $item) {
-            if ('object' === $item[0]) {
-                $formattedValue = sprintf('object(%s)', $item[1]);
-            } elseif ('array' === $item[0]) {
-                $formattedValue = sprintf('array(%s)', \is_array($item[1]) ? $this->formatArgs($item[1]) : $item[1]);
-            } elseif ('null' === $item[0]) {
-                $formattedValue = 'null';
-            } elseif ('boolean' === $item[0]) {
-                $formattedValue = strtolower(var_export($item[1], true));
-            } elseif ('resource' === $item[0]) {
-                $formattedValue = 'resource';
-            } else {
-                $formattedValue = str_replace("\n", '', $this->escapeXml(var_export($item[1], true)));
-            }
-
-            $result[] = \is_int($key) ? $formattedValue : sprintf("'%s' => %s", $this->escapeXml($key), $formattedValue);
-        }
-
-        return implode(', ', $result);
-    }
-}
diff --git a/src/Symfony/Component/ErrorRenderer/Exception/ErrorRendererNotFoundException.php b/src/Symfony/Component/ErrorRenderer/Exception/ErrorRendererNotFoundException.php
deleted file mode 100644
index 4020ced161fc1..0000000000000
--- a/src/Symfony/Component/ErrorRenderer/Exception/ErrorRendererNotFoundException.php
+++ /dev/null
@@ -1,16 +0,0 @@
-<?php
-
-/*
- * This file is part of the Symfony package.
- *
- * (c) Fabien Potencier <fabien@symfony.com>
- *
- * For the full copyright and license information, please view the LICENSE
- * file that was distributed with this source code.
- */
-
-namespace Symfony\Component\ErrorRenderer\Exception;
-
-class ErrorRendererNotFoundException extends \RuntimeException
-{
-}
diff --git a/src/Symfony/Component/ErrorRenderer/LICENSE b/src/Symfony/Component/ErrorRenderer/LICENSE
deleted file mode 100644
index 1a1869751d250..0000000000000
--- a/src/Symfony/Component/ErrorRenderer/LICENSE
+++ /dev/null
@@ -1,19 +0,0 @@
-Copyright (c) 2019 Fabien Potencier
-
-Permission is hereby granted, free of charge, to any person obtaining a copy
-of this software and associated documentation files (the "Software"), to deal
-in the Software without restriction, including without limitation the rights
-to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
-copies of the Software, and to permit persons to whom the Software is furnished
-to do so, subject to the following conditions:
-
-The above copyright notice and this permission notice shall be included in all
-copies or substantial portions of the Software.
-
-THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
-IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
-FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
-AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
-LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
-OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
-THE SOFTWARE.
diff --git a/src/Symfony/Component/ErrorRenderer/README.md b/src/Symfony/Component/ErrorRenderer/README.md
deleted file mode 100644
index 272c2924d89d3..0000000000000
--- a/src/Symfony/Component/ErrorRenderer/README.md
+++ /dev/null
@@ -1,12 +0,0 @@
-ErrorRenderer Component
-======================
-
-The ErrorRenderer component provides tools to display errors and exceptions.
-
-Resources
----------
-
-  * [Contributing](https://symfony.com/doc/current/contributing/index.html)
-  * [Report issues](https://github.com/symfony/symfony/issues) and
-    [send Pull Requests](https://github.com/symfony/symfony/pulls)
-    in the [main Symfony repository](https://github.com/symfony/symfony)
diff --git a/src/Symfony/Component/ErrorRenderer/Resources/views/exception_full.html.php b/src/Symfony/Component/ErrorRenderer/Resources/views/exception_full.html.php
deleted file mode 100644
index 7ce8de0666df1..0000000000000
--- a/src/Symfony/Component/ErrorRenderer/Resources/views/exception_full.html.php
+++ /dev/null
@@ -1,41 +0,0 @@
-<!-- <?= $_message = sprintf('%s (%d %s)', $exceptionMessage, $statusCode, $statusText); ?> -->
-<!DOCTYPE html>
-<html lang="en">
-    <head>
-        <meta charset="<?= $this->charset; ?>" />
-        <meta name="robots" content="noindex,nofollow" />
-        <meta name="viewport" content="width=device-width,initial-scale=1" />
-        <title><?= $_message; ?></title>
-        <link rel="icon" type="image/png" href="<?= $this->include('assets/images/favicon.png.base64'); ?>">
-        <style><?= $this->include('assets/css/exception.css'); ?></style>
-        <style><?= $this->include('assets/css/exception_full.css'); ?></style>
-    </head>
-    <body>
-        <header>
-            <div class="container">
-                <h1 class="logo"><?= $this->include('assets/images/symfony-logo.svg'); ?> Symfony Exception</h1>
-
-                <div class="help-link">
-                    <a href="https://symfony.com/doc/<?= Symfony\Component\HttpKernel\Kernel::VERSION; ?>/index.html">
-                        <span class="icon"><?= $this->include('assets/images/icon-book.svg'); ?></span>
-                        <span class="hidden-xs-down">Symfony</span> Docs
-                    </a>
-                </div>
-
-                <div class="help-link">
-                    <a href="https://symfony.com/support">
-                        <span class="icon"><?= $this->include('assets/images/icon-support.svg'); ?></span>
-                        <span class="hidden-xs-down">Symfony</span> Support
-                    </a>
-                </div>
-            </div>
-        </header>
-
-        <?= $this->include('views/exception.html.php', $context); ?>
-
-        <script>
-            <?= $this->include('assets/js/exception.js'); ?>
-        </script>
-    </body>
-</html>
-<!-- <?= $_message; ?> -->
diff --git a/src/Symfony/Component/ErrorRenderer/Tests/Command/DebugCommandTest.php b/src/Symfony/Component/ErrorRenderer/Tests/Command/DebugCommandTest.php
deleted file mode 100644
index c5a9768c8bb5a..0000000000000
--- a/src/Symfony/Component/ErrorRenderer/Tests/Command/DebugCommandTest.php
+++ /dev/null
@@ -1,88 +0,0 @@
-<?php
-
-/*
- * This file is part of the Symfony package.
- *
- * (c) Fabien Potencier <fabien@symfony.com>
- *
- * For the full copyright and license information, please view the LICENSE
- * file that was distributed with this source code.
- */
-
-namespace Symfony\Component\ErrorRenderer\Tests\Command;
-
-use PHPUnit\Framework\TestCase;
-use Symfony\Component\Console\Application;
-use Symfony\Component\Console\Tester\CommandTester;
-use Symfony\Component\ErrorRenderer\Command\DebugCommand;
-use Symfony\Component\ErrorRenderer\ErrorRenderer\JsonErrorRenderer;
-use Symfony\Component\ErrorRenderer\ErrorRenderer\TxtErrorRenderer;
-use Symfony\Component\ErrorRenderer\ErrorRenderer\XmlErrorRenderer;
-
-class DebugCommandTest extends TestCase
-{
-    public function testAvailableRenderers()
-    {
-        $tester = $this->createCommandTester();
-        $ret = $tester->execute([], ['decorated' => false]);
-
-        $this->assertEquals(0, $ret, 'Returns 0 in case of success');
-        $this->assertSame(<<<TXT
-
-Error Renderers
-===============
-
- The following error renderers are available:
-
- -------- ----------------------------------------------------------------- 
-  Format   Class                                                            
- -------- ----------------------------------------------------------------- 
-  json     Symfony\Component\ErrorRenderer\ErrorRenderer\JsonErrorRenderer  
-  xml      Symfony\Component\ErrorRenderer\ErrorRenderer\XmlErrorRenderer   
-  txt      Symfony\Component\ErrorRenderer\ErrorRenderer\TxtErrorRenderer   
- -------- ----------------------------------------------------------------- 
-
-
-TXT
-            , $tester->getDisplay(true));
-    }
-
-    public function testFormatArgument()
-    {
-        $tester = $this->createCommandTester();
-        $ret = $tester->execute(['format' => 'json'], ['decorated' => false]);
-
-        $this->assertEquals(0, $ret, 'Returns 0 in case of success');
-        $this->assertSame(<<<TXT
-{
-    "title": "Internal Server Error",
-    "status": 500,
-    "detail": "Whoops, looks like something went wrong."
-}
-
-TXT
-            , $tester->getDisplay(true));
-    }
-
-    private function createCommandTester()
-    {
-        $command = new DebugCommand([
-            'json' => new JsonErrorRenderer(false),
-            'xml' => new XmlErrorRenderer(false),
-            'txt' => new TxtErrorRenderer(false),
-        ]);
-
-        $application = new Application();
-        $application->add($command);
-
-        return new CommandTester($application->find('debug:error-renderer'));
-    }
-
-    public function testInvalidFormat()
-    {
-        $this->expectException('Symfony\Component\Console\Exception\InvalidArgumentException');
-        $this->expectExceptionMessage('No error renderer found for format "foo". Known format are json, xml, txt.');
-        $tester = $this->createCommandTester();
-        $tester->execute(['format' => 'foo'], ['decorated' => false]);
-    }
-}
diff --git a/src/Symfony/Component/ErrorRenderer/Tests/DependencyInjection/ErrorRendererPassTest.php b/src/Symfony/Component/ErrorRenderer/Tests/DependencyInjection/ErrorRendererPassTest.php
deleted file mode 100644
index e69fd860b85d8..0000000000000
--- a/src/Symfony/Component/ErrorRenderer/Tests/DependencyInjection/ErrorRendererPassTest.php
+++ /dev/null
@@ -1,67 +0,0 @@
-<?php
-
-/*
- * This file is part of the Symfony package.
- *
- * (c) Fabien Potencier <fabien@symfony.com>
- *
- * For the full copyright and license information, please view the LICENSE
- * file that was distributed with this source code.
- */
-
-namespace Symfony\Component\ErrorRenderer\Tests\DependencyInjection;
-
-use PHPUnit\Framework\TestCase;
-use Symfony\Component\DependencyInjection\Argument\ServiceClosureArgument;
-use Symfony\Component\DependencyInjection\ContainerBuilder;
-use Symfony\Component\DependencyInjection\Reference;
-use Symfony\Component\DependencyInjection\ServiceLocator;
-use Symfony\Component\ErrorRenderer\DependencyInjection\ErrorRendererPass;
-use Symfony\Component\ErrorRenderer\DependencyInjection\LazyLoadingErrorRenderer;
-use Symfony\Component\ErrorRenderer\ErrorRenderer\HtmlErrorRenderer;
-use Symfony\Component\ErrorRenderer\ErrorRenderer\JsonErrorRenderer;
-
-class ErrorRendererPassTest extends TestCase
-{
-    public function testProcess()
-    {
-        $container = new ContainerBuilder();
-        $container->setParameter('kernel.debug', true);
-        $definition = $container->register('error_renderer', LazyLoadingErrorRenderer::class)
-            ->addArgument([])
-        ;
-        $container->register('error_renderer.renderer.html', HtmlErrorRenderer::class)
-            ->addTag('error_renderer.renderer')
-        ;
-        $container->register('error_renderer.renderer.json', JsonErrorRenderer::class)
-            ->addTag('error_renderer.renderer')
-        ;
-
-        (new ErrorRendererPass())->process($container);
-
-        $serviceLocatorDefinition = $container->getDefinition((string) $definition->getArgument(0));
-        $this->assertSame(ServiceLocator::class, $serviceLocatorDefinition->getClass());
-
-        $expected = [
-            'html' => new ServiceClosureArgument(new Reference('error_renderer.renderer.html')),
-            'json' => new ServiceClosureArgument(new Reference('error_renderer.renderer.json')),
-        ];
-        $this->assertEquals($expected, $serviceLocatorDefinition->getArgument(0));
-    }
-
-    public function testServicesAreOrderedAccordingToPriority()
-    {
-        $container = new ContainerBuilder();
-        $definition = $container->register('error_renderer')->setArguments([null]);
-        $container->register('r2')->addTag('error_renderer.renderer', ['format' => 'json', 'priority' => 100]);
-        $container->register('r1')->addTag('error_renderer.renderer', ['format' => 'json', 'priority' => 200]);
-        $container->register('r3')->addTag('error_renderer.renderer', ['format' => 'json']);
-        (new ErrorRendererPass())->process($container);
-
-        $expected = [
-            'json' => new ServiceClosureArgument(new Reference('r1')),
-        ];
-        $serviceLocatorDefinition = $container->getDefinition((string) $definition->getArgument(0));
-        $this->assertEquals($expected, $serviceLocatorDefinition->getArgument(0));
-    }
-}
diff --git a/src/Symfony/Component/ErrorRenderer/Tests/DependencyInjection/LazyLoadingErrorRendererTest.php b/src/Symfony/Component/ErrorRenderer/Tests/DependencyInjection/LazyLoadingErrorRendererTest.php
deleted file mode 100644
index 5811a0c026e0e..0000000000000
--- a/src/Symfony/Component/ErrorRenderer/Tests/DependencyInjection/LazyLoadingErrorRendererTest.php
+++ /dev/null
@@ -1,66 +0,0 @@
-<?php
-
-/*
- * This file is part of the Symfony package.
- *
- * (c) Fabien Potencier <fabien@symfony.com>
- *
- * For the full copyright and license information, please view the LICENSE
- * file that was distributed with this source code.
- */
-
-namespace Symfony\Component\ErrorRenderer\Tests\DependencyInjection;
-
-use PHPUnit\Framework\TestCase;
-use Psr\Container\ContainerInterface;
-use Symfony\Component\ErrorRenderer\DependencyInjection\LazyLoadingErrorRenderer;
-use Symfony\Component\ErrorRenderer\ErrorRenderer\ErrorRendererInterface;
-use Symfony\Component\ErrorRenderer\Exception\FlattenException;
-
-class LazyLoadingErrorRendererTest extends TestCase
-{
-    public function testInvalidErrorRenderer()
-    {
-        $this->expectException('Symfony\Component\ErrorRenderer\Exception\ErrorRendererNotFoundException');
-        $this->expectExceptionMessage('No error renderer found for format "foo".');
-        $container = $this->getMockBuilder(ContainerInterface::class)->getMock();
-        $container->expects($this->once())->method('has')->with('foo')->willReturn(false);
-
-        $exception = FlattenException::createFromThrowable(new \Exception('Foo'));
-        (new LazyLoadingErrorRenderer($container))->render($exception, 'foo');
-    }
-
-    public function testCustomErrorRenderer()
-    {
-        $container = $this->getMockBuilder(ContainerInterface::class)->getMock();
-        $container
-            ->expects($this->once())
-            ->method('has')
-            ->with('foo')
-            ->willReturn(true)
-        ;
-        $container
-            ->expects($this->once())
-            ->method('get')
-            ->willReturn(new FooErrorRenderer())
-        ;
-
-        $errorRenderer = new LazyLoadingErrorRenderer($container);
-
-        $exception = FlattenException::createFromThrowable(new \RuntimeException('Foo'));
-        $this->assertSame('Foo', $errorRenderer->render($exception, 'foo'));
-    }
-}
-
-class FooErrorRenderer implements ErrorRendererInterface
-{
-    public static function getFormat(): string
-    {
-        return 'foo';
-    }
-
-    public function render(FlattenException $exception): string
-    {
-        return $exception->getMessage();
-    }
-}
diff --git a/src/Symfony/Component/ErrorRenderer/Tests/ErrorRenderer/JsonErrorRendererTest.php b/src/Symfony/Component/ErrorRenderer/Tests/ErrorRenderer/JsonErrorRendererTest.php
deleted file mode 100644
index 55e6d5cdf227d..0000000000000
--- a/src/Symfony/Component/ErrorRenderer/Tests/ErrorRenderer/JsonErrorRendererTest.php
+++ /dev/null
@@ -1,76 +0,0 @@
-<?php
-
-/*
- * This file is part of the Symfony package.
- *
- * (c) Fabien Potencier <fabien@symfony.com>
- *
- * For the full copyright and license information, please view the LICENSE
- * file that was distributed with this source code.
- */
-
-namespace Symfony\Component\ErrorRenderer\Tests\ErrorRenderer;
-
-use PHPUnit\Framework\TestCase;
-use Symfony\Component\ErrorRenderer\ErrorRenderer\ErrorRendererInterface;
-use Symfony\Component\ErrorRenderer\ErrorRenderer\JsonErrorRenderer;
-use Symfony\Component\ErrorRenderer\Exception\FlattenException;
-
-class JsonErrorRendererTest extends TestCase
-{
-    /**
-     * @dataProvider getRenderData
-     */
-    public function testRender(FlattenException $exception, ErrorRendererInterface $errorRenderer, string $expected)
-    {
-        $this->assertStringMatchesFormat($expected, $errorRenderer->render($exception));
-    }
-
-    public function getRenderData(): iterable
-    {
-        $expectedDebug = <<<JSON
-{
-    "title": "Internal Server Error",
-    "status": 500,
-    "detail": "Foo",
-    "exceptions": [
-        {
-            "message": "Foo",
-            "class": "RuntimeException",
-            "trace": [
-%A
-JSON;
-
-        $expectedNonDebug = <<<JSON
-{
-    "title": "Internal Server Error",
-    "status": 500,
-    "detail": "Whoops, looks like something went wrong."
-}
-JSON;
-
-        yield '->render() returns the JSON content WITH stack traces in debug mode' => [
-            FlattenException::createFromThrowable(new \RuntimeException('Foo')),
-            new JsonErrorRenderer(true),
-            $expectedDebug,
-        ];
-
-        yield '->render() returns the JSON content WITHOUT stack traces in non-debug mode' => [
-            FlattenException::createFromThrowable(new \RuntimeException('Foo')),
-            new JsonErrorRenderer(false),
-            $expectedNonDebug,
-        ];
-
-        yield '->render() returns the JSON content WITHOUT stack traces in debug mode FORCING non-debug via X-Debug header' => [
-            FlattenException::createFromThrowable(new \RuntimeException('Foo'), null, ['X-Debug' => false]),
-            new JsonErrorRenderer(true),
-            $expectedNonDebug,
-        ];
-
-        yield '->render() returns the JSON content WITHOUT stack traces in non-debug mode EVEN FORCING debug via X-Debug header' => [
-            FlattenException::createFromThrowable(new \RuntimeException('Foo'), null, ['X-Debug' => true]),
-            new JsonErrorRenderer(false),
-            $expectedNonDebug,
-        ];
-    }
-}
diff --git a/src/Symfony/Component/ErrorRenderer/Tests/ErrorRenderer/TxtErrorRendererTest.php b/src/Symfony/Component/ErrorRenderer/Tests/ErrorRenderer/TxtErrorRendererTest.php
deleted file mode 100644
index b6c1570df88d7..0000000000000
--- a/src/Symfony/Component/ErrorRenderer/Tests/ErrorRenderer/TxtErrorRendererTest.php
+++ /dev/null
@@ -1,69 +0,0 @@
-<?php
-
-/*
- * This file is part of the Symfony package.
- *
- * (c) Fabien Potencier <fabien@symfony.com>
- *
- * For the full copyright and license information, please view the LICENSE
- * file that was distributed with this source code.
- */
-
-namespace Symfony\Component\ErrorRenderer\Tests\ErrorRenderer;
-
-use PHPUnit\Framework\TestCase;
-use Symfony\Component\ErrorRenderer\ErrorRenderer\ErrorRendererInterface;
-use Symfony\Component\ErrorRenderer\ErrorRenderer\TxtErrorRenderer;
-use Symfony\Component\ErrorRenderer\Exception\FlattenException;
-
-class TxtErrorRendererTest extends TestCase
-{
-    /**
-     * @dataProvider getRenderData
-     */
-    public function testRender(FlattenException $exception, ErrorRendererInterface $errorRenderer, string $expected)
-    {
-        $this->assertStringMatchesFormat($expected, $errorRenderer->render($exception));
-    }
-
-    public function getRenderData(): iterable
-    {
-        $expectedDebug = <<<TXT
-[title] Internal Server Error
-[status] 500
-[detail] Foo
-[1] RuntimeException: Foo
-in %A
-TXT;
-
-        $expectedNonDebug = <<<TXT
-[title] Internal Server Error
-[status] 500
-[detail] Whoops, looks like something went wrong.
-TXT;
-
-        yield '->render() returns the TXT content WITH stack traces in debug mode' => [
-            FlattenException::createFromThrowable(new \RuntimeException('Foo')),
-            new TxtErrorRenderer(true),
-            $expectedDebug,
-        ];
-
-        yield '->render() returns the TXT content WITHOUT stack traces in non-debug mode' => [
-            FlattenException::createFromThrowable(new \RuntimeException('Foo')),
-            new TxtErrorRenderer(false),
-            $expectedNonDebug,
-        ];
-
-        yield '->render() returns the TXT content WITHOUT stack traces in debug mode FORCING non-debug via X-Debug header' => [
-            FlattenException::createFromThrowable(new \RuntimeException('Foo'), null, ['X-Debug' => false]),
-            new TxtErrorRenderer(true),
-            $expectedNonDebug,
-        ];
-
-        yield '->render() returns the TXT content WITHOUT stack traces in non-debug mode EVEN FORCING debug via X-Debug header' => [
-            FlattenException::createFromThrowable(new \RuntimeException('Foo'), null, ['X-Debug' => true]),
-            new TxtErrorRenderer(false),
-            $expectedNonDebug,
-        ];
-    }
-}
diff --git a/src/Symfony/Component/ErrorRenderer/Tests/ErrorRenderer/XmlErrorRendererTest.php b/src/Symfony/Component/ErrorRenderer/Tests/ErrorRenderer/XmlErrorRendererTest.php
deleted file mode 100644
index 3a756720ecc46..0000000000000
--- a/src/Symfony/Component/ErrorRenderer/Tests/ErrorRenderer/XmlErrorRendererTest.php
+++ /dev/null
@@ -1,75 +0,0 @@
-<?php
-
-/*
- * This file is part of the Symfony package.
- *
- * (c) Fabien Potencier <fabien@symfony.com>
- *
- * For the full copyright and license information, please view the LICENSE
- * file that was distributed with this source code.
- */
-
-namespace Symfony\Component\ErrorRenderer\Tests\ErrorRenderer;
-
-use PHPUnit\Framework\TestCase;
-use Symfony\Component\ErrorRenderer\ErrorRenderer\ErrorRendererInterface;
-use Symfony\Component\ErrorRenderer\ErrorRenderer\XmlErrorRenderer;
-use Symfony\Component\ErrorRenderer\Exception\FlattenException;
-
-class XmlErrorRendererTest extends TestCase
-{
-    /**
-     * @dataProvider getRenderData
-     */
-    public function testRender(FlattenException $exception, ErrorRendererInterface $errorRenderer, string $expected)
-    {
-        $this->assertStringMatchesFormat($expected, $errorRenderer->render($exception));
-    }
-
-    public function getRenderData(): iterable
-    {
-        $expectedDebug = <<<XML
-<?xml version="1.0" encoding="UTF-8" ?>
-<problem xmlns="urn:ietf:rfc:7807">
-    <title>Internal Server Error</title>
-    <status>500</status>
-    <detail>Foo</detail>
-    <exceptions><exception class="RuntimeException" message="Foo"><traces><trace>%A</trace></traces></exception></exceptions>
-</problem>
-XML;
-
-        $expectedNonDebug = <<<XML
-<?xml version="1.0" encoding="UTF-8" ?>
-<problem xmlns="urn:ietf:rfc:7807">
-    <title>Internal Server Error</title>
-    <status>500</status>
-    <detail>Whoops, looks like something went wrong.</detail>
-    
-</problem>
-XML;
-
-        yield '->render() returns the XML content WITH stack traces in debug mode' => [
-            FlattenException::createFromThrowable(new \RuntimeException('Foo')),
-            new XmlErrorRenderer(true),
-            $expectedDebug,
-        ];
-
-        yield '->render() returns the XML content WITHOUT stack traces in non-debug mode' => [
-            FlattenException::createFromThrowable(new \RuntimeException('Foo')),
-            new XmlErrorRenderer(false),
-            $expectedNonDebug,
-        ];
-
-        yield '->render() returns the XML content WITHOUT stack traces in debug mode FORCING non-debug via X-Debug header' => [
-            FlattenException::createFromThrowable(new \RuntimeException('Foo'), null, ['X-Debug' => false]),
-            new XmlErrorRenderer(true),
-            $expectedNonDebug,
-        ];
-
-        yield '->render() returns the XML content WITHOUT stack traces in non-debug mode EVEN FORCING debug via X-Debug header' => [
-            FlattenException::createFromThrowable(new \RuntimeException('Foo'), null, ['X-Debug' => true]),
-            new XmlErrorRenderer(false),
-            $expectedNonDebug,
-        ];
-    }
-}
diff --git a/src/Symfony/Component/ErrorRenderer/Tests/ErrorRendererTest.php b/src/Symfony/Component/ErrorRenderer/Tests/ErrorRendererTest.php
deleted file mode 100644
index 11ef6a7d7eb4f..0000000000000
--- a/src/Symfony/Component/ErrorRenderer/Tests/ErrorRendererTest.php
+++ /dev/null
@@ -1,56 +0,0 @@
-<?php
-
-/*
- * This file is part of the Symfony package.
- *
- * (c) Fabien Potencier <fabien@symfony.com>
- *
- * For the full copyright and license information, please view the LICENSE
- * file that was distributed with this source code.
- */
-
-namespace Symfony\Component\ErrorRenderer\Tests;
-
-use PHPUnit\Framework\TestCase;
-use Symfony\Component\ErrorRenderer\ErrorRenderer;
-use Symfony\Component\ErrorRenderer\ErrorRenderer\ErrorRendererInterface;
-use Symfony\Component\ErrorRenderer\Exception\FlattenException;
-
-class ErrorRendererTest extends TestCase
-{
-    public function testErrorRendererNotFound()
-    {
-        $this->expectException('Symfony\Component\ErrorRenderer\Exception\ErrorRendererNotFoundException');
-        $this->expectExceptionMessage('No error renderer found for format "foo".');
-        $exception = FlattenException::createFromThrowable(new \Exception('foo'));
-        (new ErrorRenderer([]))->render($exception, 'foo');
-    }
-
-    public function testInvalidErrorRenderer()
-    {
-        $this->expectException('TypeError');
-        new ErrorRenderer([new \stdClass()]);
-    }
-
-    public function testCustomErrorRenderer()
-    {
-        $renderers = [new FooErrorRenderer()];
-        $errorRenderer = new ErrorRenderer($renderers);
-
-        $exception = FlattenException::createFromThrowable(new \RuntimeException('Foo'));
-        $this->assertSame('Foo', $errorRenderer->render($exception, 'foo'));
-    }
-}
-
-class FooErrorRenderer implements ErrorRendererInterface
-{
-    public static function getFormat(): string
-    {
-        return 'foo';
-    }
-
-    public function render(FlattenException $exception): string
-    {
-        return $exception->getMessage();
-    }
-}
diff --git a/src/Symfony/Component/ErrorRenderer/composer.json b/src/Symfony/Component/ErrorRenderer/composer.json
deleted file mode 100644
index 90351239fc689..0000000000000
--- a/src/Symfony/Component/ErrorRenderer/composer.json
+++ /dev/null
@@ -1,47 +0,0 @@
-{
-    "name": "symfony/error-renderer",
-    "type": "library",
-    "description": "Symfony ErrorRenderer Component",
-    "keywords": [],
-    "homepage": "https://symfony.com",
-    "license": "MIT",
-    "authors": [
-        {
-            "name": "Fabien Potencier",
-            "email": "fabien@symfony.com"
-        },
-        {
-            "name": "Yonel Ceruto",
-            "email": "yonelceruto@gmail.com"
-        },
-        {
-            "name": "Symfony Community",
-            "homepage": "https://symfony.com/contributors"
-        }
-    ],
-    "require": {
-        "php": "^7.1.3",
-        "psr/log": "~1.0",
-        "symfony/debug": "^4.4"
-    },
-    "require-dev": {
-        "symfony/console": "^4.4",
-        "symfony/dependency-injection": "^4.4",
-        "symfony/http-kernel": "^4.4"
-    },
-    "conflict": {
-        "symfony/http-kernel": "<4.4"
-    },
-    "autoload": {
-        "psr-4": { "Symfony\\Component\\ErrorRenderer\\": "" },
-        "exclude-from-classmap": [
-            "/Tests/"
-        ]
-    },
-    "minimum-stability": "dev",
-    "extra": {
-        "branch-alias": {
-            "dev-master": "4.4-dev"
-        }
-    }
-}
diff --git a/src/Symfony/Component/ErrorRenderer/phpunit.xml.dist b/src/Symfony/Component/ErrorRenderer/phpunit.xml.dist
deleted file mode 100644
index c4c29459f3e74..0000000000000
--- a/src/Symfony/Component/ErrorRenderer/phpunit.xml.dist
+++ /dev/null
@@ -1,30 +0,0 @@
-<?xml version="1.0" encoding="UTF-8"?>
-
-<phpunit xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
-         xsi:noNamespaceSchemaLocation="http://schema.phpunit.de/5.2/phpunit.xsd"
-         backupGlobals="false"
-         colors="true"
-         bootstrap="vendor/autoload.php"
-         failOnRisky="true"
-         failOnWarning="true"
->
-    <php>
-        <ini name="error_reporting" value="-1" />
-    </php>
-
-    <testsuites>
-        <testsuite name="Symfony ErrorRenderer Component Test Suite">
-            <directory>./Tests/</directory>
-        </testsuite>
-    </testsuites>
-
-    <filter>
-        <whitelist>
-            <directory>./</directory>
-            <exclude>
-                <directory>./Tests</directory>
-                <directory>./vendor</directory>
-            </exclude>
-        </whitelist>
-    </filter>
-</phpunit>
diff --git a/src/Symfony/Component/HttpKernel/Controller/ErrorController.php b/src/Symfony/Component/HttpKernel/Controller/ErrorController.php
index a86fa5c5cf391..b6c440103ffd3 100644
--- a/src/Symfony/Component/HttpKernel/Controller/ErrorController.php
+++ b/src/Symfony/Component/HttpKernel/Controller/ErrorController.php
@@ -11,11 +11,10 @@
 
 namespace Symfony\Component\HttpKernel\Controller;
 
-use Symfony\Component\ErrorRenderer\ErrorRenderer;
-use Symfony\Component\ErrorRenderer\Exception\ErrorRendererNotFoundException;
-use Symfony\Component\ErrorRenderer\Exception\FlattenException;
+use Symfony\Component\ErrorHandler\ErrorRenderer\ErrorRendererInterface;
 use Symfony\Component\HttpFoundation\Request;
 use Symfony\Component\HttpFoundation\Response;
+use Symfony\Component\HttpKernel\Exception\HttpException;
 use Symfony\Component\HttpKernel\HttpKernelInterface;
 
 /**
@@ -30,26 +29,22 @@ class ErrorController
     private $controller;
     private $errorRenderer;
 
-    public function __construct(HttpKernelInterface $kernel, $controller, ErrorRenderer $errorRenderer)
+    public function __construct(HttpKernelInterface $kernel, $controller, ErrorRendererInterface $errorRenderer)
     {
         $this->kernel = $kernel;
         $this->controller = $controller;
         $this->errorRenderer = $errorRenderer;
     }
 
-    public function __invoke(Request $request, FlattenException $exception): Response
+    public function __invoke(\Throwable $exception): Response
     {
-        try {
-            return new Response($this->errorRenderer->render($exception, $request->getPreferredFormat()), $exception->getStatusCode(), $exception->getHeaders());
-        } catch (ErrorRendererNotFoundException $_) {
-            return new Response($this->errorRenderer->render($exception), $exception->getStatusCode(), $exception->getHeaders());
-        }
+        $exception = $this->errorRenderer->render($exception);
+
+        return new Response($exception->getAsString(), $exception->getStatusCode(), $exception->getHeaders());
     }
 
     public function preview(Request $request, int $code): Response
     {
-        $exception = FlattenException::createFromThrowable(new \Exception('This is a sample exception.'), $code, ['X-Debug' => false]);
-
         /*
          * This Request mimics the parameters set by
          * \Symfony\Component\HttpKernel\EventListener\ErrorListener::duplicateRequest, with
@@ -57,7 +52,7 @@ public function preview(Request $request, int $code): Response
          */
         $subRequest = $request->duplicate(null, null, [
             '_controller' => $this->controller,
-            'exception' => $exception,
+            'exception' => new HttpException($code, 'This is a sample exception.'),
             'logger' => null,
             'showException' => false,
         ]);
diff --git a/src/Symfony/Component/HttpKernel/DataCollector/ExceptionDataCollector.php b/src/Symfony/Component/HttpKernel/DataCollector/ExceptionDataCollector.php
index 08e79c53e12ac..0a00a2e40e680 100644
--- a/src/Symfony/Component/HttpKernel/DataCollector/ExceptionDataCollector.php
+++ b/src/Symfony/Component/HttpKernel/DataCollector/ExceptionDataCollector.php
@@ -11,7 +11,7 @@
 
 namespace Symfony\Component\HttpKernel\DataCollector;
 
-use Symfony\Component\ErrorRenderer\Exception\FlattenException;
+use Symfony\Component\ErrorHandler\Exception\FlattenException;
 use Symfony\Component\HttpFoundation\Request;
 use Symfony\Component\HttpFoundation\Response;
 
diff --git a/src/Symfony/Component/HttpKernel/EventListener/ErrorListener.php b/src/Symfony/Component/HttpKernel/EventListener/ErrorListener.php
index 9a16cde741432..472c3a2383f07 100644
--- a/src/Symfony/Component/HttpKernel/EventListener/ErrorListener.php
+++ b/src/Symfony/Component/HttpKernel/EventListener/ErrorListener.php
@@ -12,10 +12,11 @@
 namespace Symfony\Component\HttpKernel\EventListener;
 
 use Psr\Log\LoggerInterface;
-use Symfony\Component\ErrorRenderer\Exception\FlattenException;
+use Symfony\Component\ErrorHandler\Exception\FlattenException;
 use Symfony\Component\EventDispatcher\EventDispatcherInterface;
 use Symfony\Component\EventDispatcher\EventSubscriberInterface;
 use Symfony\Component\HttpFoundation\Request;
+use Symfony\Component\HttpKernel\Event\ControllerArgumentsEvent;
 use Symfony\Component\HttpKernel\Event\ExceptionEvent;
 use Symfony\Component\HttpKernel\Exception\HttpExceptionInterface;
 use Symfony\Component\HttpKernel\HttpKernelInterface;
@@ -87,9 +88,28 @@ public function onKernelException(ExceptionEvent $event)
         }
     }
 
+    public function onControllerArguments(ControllerArgumentsEvent $event)
+    {
+        $e = $event->getRequest()->attributes->get('exception');
+
+        if (!$e instanceof \Throwable || false === $k = array_search($e, $event->getArguments(), true)) {
+            return;
+        }
+
+        $r = new \ReflectionFunction(\Closure::fromCallable($event->getController()));
+        $r = $r->getParameters()[$k] ?? null;
+
+        if ($r && $r->hasType() && FlattenException::class === $r->getType()->getName()) {
+            $arguments = $event->getArguments();
+            $arguments[$k] = FlattenException::createFromThrowable($e);
+            $event->setArguments($arguments);
+        }
+    }
+
     public static function getSubscribedEvents()
     {
         return [
+            KernelEvents::CONTROLLER_ARGUMENTS => 'onControllerArguments',
             KernelEvents::EXCEPTION => [
                 ['logKernelException', 0],
                 ['onKernelException', -128],
@@ -123,7 +143,7 @@ protected function duplicateRequest(\Exception $exception, Request $request)
     {
         $attributes = [
             '_controller' => $this->controller,
-            'exception' => FlattenException::createFromThrowable($exception),
+            'exception' => $exception,
             'logger' => $this->logger instanceof DebugLoggerInterface ? $this->logger : null,
         ];
         $request = $request->duplicate(null, null, $attributes);
diff --git a/src/Symfony/Component/HttpKernel/EventListener/ExceptionListener.php b/src/Symfony/Component/HttpKernel/EventListener/ExceptionListener.php
index dc2fd818ce93a..aa4349428ad12 100644
--- a/src/Symfony/Component/HttpKernel/EventListener/ExceptionListener.php
+++ b/src/Symfony/Component/HttpKernel/EventListener/ExceptionListener.php
@@ -12,7 +12,7 @@
 namespace Symfony\Component\HttpKernel\EventListener;
 
 use Psr\Log\LoggerInterface;
-use Symfony\Component\ErrorRenderer\Exception\FlattenException;
+use Symfony\Component\ErrorHandler\Exception\FlattenException;
 use Symfony\Component\EventDispatcher\EventDispatcherInterface;
 use Symfony\Component\EventDispatcher\EventSubscriberInterface;
 use Symfony\Component\HttpFoundation\Request;
diff --git a/src/Symfony/Component/HttpKernel/Tests/Controller/ErrorControllerTest.php b/src/Symfony/Component/HttpKernel/Tests/Controller/ErrorControllerTest.php
index 4a64af3ab1e33..a857615f1c3d3 100644
--- a/src/Symfony/Component/HttpKernel/Tests/Controller/ErrorControllerTest.php
+++ b/src/Symfony/Component/HttpKernel/Tests/Controller/ErrorControllerTest.php
@@ -12,10 +12,8 @@
 namespace Symfony\Component\HttpKernel\Tests\Controller;
 
 use PHPUnit\Framework\TestCase;
-use Symfony\Component\ErrorRenderer\ErrorRenderer;
-use Symfony\Component\ErrorRenderer\ErrorRenderer\HtmlErrorRenderer;
-use Symfony\Component\ErrorRenderer\ErrorRenderer\JsonErrorRenderer;
-use Symfony\Component\ErrorRenderer\Exception\FlattenException;
+use Symfony\Component\ErrorHandler\ErrorRenderer\HtmlErrorRenderer;
+use Symfony\Component\ErrorHandler\Exception\FlattenException;
 use Symfony\Component\HttpFoundation\Request;
 use Symfony\Component\HttpFoundation\Response;
 use Symfony\Component\HttpKernel\Controller\ErrorController;
@@ -28,12 +26,12 @@ class ErrorControllerTest extends TestCase
     /**
      * @dataProvider getInvokeControllerDataProvider
      */
-    public function testInvokeController(Request $request, FlattenException $exception, int $statusCode, string $content)
+    public function testInvokeController(Request $request, \Exception $exception, int $statusCode, string $content)
     {
         $kernel = $this->getMockBuilder(HttpKernelInterface::class)->getMock();
-        $errorRenderer = new ErrorRenderer([new HtmlErrorRenderer(), new JsonErrorRenderer()]);
+        $errorRenderer = new HtmlErrorRenderer();
         $controller = new ErrorController($kernel, null, $errorRenderer);
-        $response = $controller($request, $exception);
+        $response = $controller($exception);
 
         $this->assertSame($statusCode, $response->getStatusCode());
         self::assertStringContainsString($content, strtr($response->getContent(), ["\n" => '', '    ' => '']));
@@ -43,50 +41,23 @@ public function getInvokeControllerDataProvider()
     {
         yield 'default status code and HTML format' => [
             new Request(),
-            FlattenException::createFromThrowable(new \Exception()),
+            new \Exception(),
             500,
             'The server returned a "500 Internal Server Error".',
         ];
 
         yield 'custom status code' => [
             new Request(),
-            FlattenException::createFromThrowable(new NotFoundHttpException('Page not found.')),
+            new NotFoundHttpException('Page not found.'),
             404,
             'The server returned a "404 Not Found".',
         ];
 
-        $request = new Request();
-        $request->attributes->set('_format', 'json');
-        yield 'custom format via _format attribute' => [
-            $request,
-            FlattenException::createFromThrowable(new \Exception('foo')),
-            500,
-            '{"title": "Internal Server Error","status": 500,"detail": "Whoops, looks like something went wrong."}',
-        ];
-
-        $request = new Request();
-        $request->headers->set('Accept', 'application/json');
-        yield 'custom format via Accept header' => [
-            $request,
-            FlattenException::createFromThrowable(new HttpException(405, 'Invalid request.')),
-            405,
-            '{"title": "Method Not Allowed","status": 405,"detail": "Whoops, looks like something went wrong."}',
-        ];
-
-        $request = new Request();
-        $request->headers->set('Content-Type', 'application/json');
-        yield 'custom format via Content-Type header' => [
-            $request,
-            FlattenException::createFromThrowable(new HttpException(405, 'Invalid request.')),
-            405,
-            '{"title": "Method Not Allowed","status": 405,"detail": "Whoops, looks like something went wrong."}',
-        ];
-
         $request = new Request();
         $request->attributes->set('_format', 'unknown');
         yield 'default HTML format for unknown formats' => [
             $request,
-            FlattenException::createFromThrowable(new HttpException(405, 'Invalid request.')),
+            new HttpException(405, 'Invalid request.'),
             405,
             'The server returned a "405 Method Not Allowed".',
         ];
@@ -106,7 +77,7 @@ public function testPreviewController()
                     $exception = $request->attributes->get('exception');
 
                     $this->assertSame($_controller, $request->attributes->get('_controller'));
-                    $this->assertInstanceOf(FlattenException::class, $exception);
+                    $this->assertInstanceOf(\Throwable::class, $exception);
                     $this->assertSame($code, $exception->getStatusCode());
                     $this->assertFalse($request->attributes->get('showException'));
 
@@ -116,7 +87,7 @@ public function testPreviewController()
             )
             ->willReturn($response = new Response());
 
-        $controller = new ErrorController($kernel, $_controller, new ErrorRenderer([]));
+        $controller = new ErrorController($kernel, $_controller, new HtmlErrorRenderer());
 
         $this->assertSame($response, $controller->preview(new Request(), $code));
     }
diff --git a/src/Symfony/Component/HttpKernel/Tests/DataCollector/ExceptionDataCollectorTest.php b/src/Symfony/Component/HttpKernel/Tests/DataCollector/ExceptionDataCollectorTest.php
index 8b1d1317d85b2..d1fc578b131f6 100644
--- a/src/Symfony/Component/HttpKernel/Tests/DataCollector/ExceptionDataCollectorTest.php
+++ b/src/Symfony/Component/HttpKernel/Tests/DataCollector/ExceptionDataCollectorTest.php
@@ -12,7 +12,7 @@
 namespace Symfony\Component\HttpKernel\Tests\DataCollector;
 
 use PHPUnit\Framework\TestCase;
-use Symfony\Component\ErrorRenderer\Exception\FlattenException;
+use Symfony\Component\ErrorHandler\Exception\FlattenException;
 use Symfony\Component\HttpFoundation\Request;
 use Symfony\Component\HttpFoundation\Response;
 use Symfony\Component\HttpKernel\DataCollector\ExceptionDataCollector;
diff --git a/src/Symfony/Component/HttpKernel/Tests/EventListener/ErrorListenerTest.php b/src/Symfony/Component/HttpKernel/Tests/EventListener/ErrorListenerTest.php
index 3707f3c4c920e..ae7149199f963 100644
--- a/src/Symfony/Component/HttpKernel/Tests/EventListener/ErrorListenerTest.php
+++ b/src/Symfony/Component/HttpKernel/Tests/EventListener/ErrorListenerTest.php
@@ -12,9 +12,13 @@
 namespace Symfony\Component\HttpKernel\Tests\EventListener;
 
 use PHPUnit\Framework\TestCase;
+use Psr\Log\LoggerInterface;
 use Symfony\Component\EventDispatcher\EventDispatcher;
+use Symfony\Component\ErrorHandler\Exception\FlattenException;
 use Symfony\Component\HttpFoundation\Request;
 use Symfony\Component\HttpFoundation\Response;
+use Symfony\Component\HttpKernel\Controller\ArgumentResolver;
+use Symfony\Component\HttpKernel\Event\ControllerArgumentsEvent;
 use Symfony\Component\HttpKernel\Event\ExceptionEvent;
 use Symfony\Component\HttpKernel\Event\ResponseEvent;
 use Symfony\Component\HttpKernel\EventListener\ErrorListener;
@@ -153,6 +157,30 @@ public function testCSPHeaderIsRemoved()
         $this->assertFalse($response->headers->has('content-security-policy'), 'CSP header has been removed');
         $this->assertFalse($dispatcher->hasListeners(KernelEvents::RESPONSE), 'CSP removal listener has been removed');
     }
+
+    public function testOnControllerArguments()
+    {
+        $controller = function (FlattenException $exception) {
+            return new Response('OK: '.$exception->getMessage());
+        };
+
+        $listener = new ErrorListener($controller, $this->createMock(LoggerInterface::class), true);
+
+        $kernel = $this->createMock(HttpKernelInterface::class);
+        $kernel->method('handle')->willReturnCallback(function (Request $request) use ($listener, $controller, $kernel) {
+            $this->assertSame($controller, $request->attributes->get('_controller'));
+            $arguments = (new ArgumentResolver())->getArguments($request, $controller);
+            $event = new ControllerArgumentsEvent($kernel, $controller, $arguments, $request, HttpKernelInterface::SUB_REQUEST);
+            $listener->onControllerArguments($event);
+
+            return $controller(...$event->getArguments());
+        });
+
+        $event = new ExceptionEvent($kernel, Request::create('/'), HttpKernelInterface::MASTER_REQUEST, new \Exception('foo'));
+        $listener->onKernelException($event);
+
+        $this->assertSame('OK: foo', $event->getResponse()->getContent());
+    }
 }
 
 class TestLogger extends Logger implements DebugLoggerInterface
diff --git a/src/Symfony/Component/HttpKernel/composer.json b/src/Symfony/Component/HttpKernel/composer.json
index 51f0d919a7ec0..ba6ab33de8e5b 100644
--- a/src/Symfony/Component/HttpKernel/composer.json
+++ b/src/Symfony/Component/HttpKernel/composer.json
@@ -18,7 +18,6 @@
     "require": {
         "php": "^7.1.3",
         "symfony/error-handler": "^4.4|^5.0",
-        "symfony/error-renderer": "^4.4|^5.0",
         "symfony/event-dispatcher": "^4.4",
         "symfony/http-foundation": "^4.4|^5.0",
         "symfony/polyfill-ctype": "^1.8",
@@ -40,7 +39,6 @@
         "symfony/templating": "^3.4|^4.0|^5.0",
         "symfony/translation": "^4.2|^5.0",
         "symfony/translation-contracts": "^1.1|^2",
-        "symfony/var-dumper": "^4.1.1|^5.0",
         "psr/cache": "~1.0",
         "twig/twig": "^1.34|^2.4|^3.0"
     },
@@ -53,15 +51,13 @@
         "symfony/console": ">=5",
         "symfony/dependency-injection": "<4.3",
         "symfony/translation": "<4.2",
-        "symfony/var-dumper": "<4.1.1",
         "twig/twig": "<1.34|<2.4,>=2"
     },
     "suggest": {
         "symfony/browser-kit": "",
         "symfony/config": "",
         "symfony/console": "",
-        "symfony/dependency-injection": "",
-        "symfony/var-dumper": ""
+        "symfony/dependency-injection": ""
     },
     "autoload": {
         "psr-4": { "Symfony\\Component\\HttpKernel\\": "" },
diff --git a/src/Symfony/Component/Messenger/EventListener/SendFailedMessageToFailureTransportListener.php b/src/Symfony/Component/Messenger/EventListener/SendFailedMessageToFailureTransportListener.php
index 0aa8fd5ea74b6..8c84cf7992786 100644
--- a/src/Symfony/Component/Messenger/EventListener/SendFailedMessageToFailureTransportListener.php
+++ b/src/Symfony/Component/Messenger/EventListener/SendFailedMessageToFailureTransportListener.php
@@ -11,7 +11,7 @@
 namespace Symfony\Component\Messenger\EventListener;
 
 use Psr\Log\LoggerInterface;
-use Symfony\Component\ErrorRenderer\Exception\FlattenException;
+use Symfony\Component\ErrorHandler\Exception\FlattenException;
 use Symfony\Component\EventDispatcher\EventSubscriberInterface;
 use Symfony\Component\Messenger\Event\WorkerMessageFailedEvent;
 use Symfony\Component\Messenger\Exception\HandlerFailedException;
diff --git a/src/Symfony/Component/Messenger/Stamp/RedeliveryStamp.php b/src/Symfony/Component/Messenger/Stamp/RedeliveryStamp.php
index 49bbf2f778571..60c3898b08606 100644
--- a/src/Symfony/Component/Messenger/Stamp/RedeliveryStamp.php
+++ b/src/Symfony/Component/Messenger/Stamp/RedeliveryStamp.php
@@ -11,7 +11,7 @@
 
 namespace Symfony\Component\Messenger\Stamp;
 
-use Symfony\Component\ErrorRenderer\Exception\FlattenException;
+use Symfony\Component\ErrorHandler\Exception\FlattenException;
 use Symfony\Component\Messenger\Envelope;
 
 /**
diff --git a/src/Symfony/Component/Messenger/Tests/Stamp/RedeliveryStampTest.php b/src/Symfony/Component/Messenger/Tests/Stamp/RedeliveryStampTest.php
index c55a670bf36fb..7fcabfc2d66f6 100644
--- a/src/Symfony/Component/Messenger/Tests/Stamp/RedeliveryStampTest.php
+++ b/src/Symfony/Component/Messenger/Tests/Stamp/RedeliveryStampTest.php
@@ -12,7 +12,7 @@
 namespace Symfony\Component\Messenger\Tests\Stamp;
 
 use PHPUnit\Framework\TestCase;
-use Symfony\Component\ErrorRenderer\Exception\FlattenException;
+use Symfony\Component\ErrorHandler\Exception\FlattenException;
 use Symfony\Component\Messenger\Stamp\RedeliveryStamp;
 
 class RedeliveryStampTest extends TestCase
diff --git a/src/Symfony/Component/Messenger/composer.json b/src/Symfony/Component/Messenger/composer.json
index 48f85f2b63d1a..62b5240b827ab 100644
--- a/src/Symfony/Component/Messenger/composer.json
+++ b/src/Symfony/Component/Messenger/composer.json
@@ -25,7 +25,6 @@
         "doctrine/persistence": "~1.0",
         "symfony/console": "^3.4|^4.0|^5.0",
         "symfony/dependency-injection": "^3.4.19|^4.1.8|^5.0",
-        "symfony/error-renderer": "^4.4|^5.0",
         "symfony/event-dispatcher": "^4.3|^5.0",
         "symfony/http-kernel": "^4.4",
         "symfony/process": "^3.4|^4.0|^5.0",
diff --git a/src/Symfony/Component/Serializer/CHANGELOG.md b/src/Symfony/Component/Serializer/CHANGELOG.md
index 0958f5054062a..7f213186e3c7f 100644
--- a/src/Symfony/Component/Serializer/CHANGELOG.md
+++ b/src/Symfony/Component/Serializer/CHANGELOG.md
@@ -6,6 +6,7 @@ CHANGELOG
 
  * deprecated the `XmlEncoder::TYPE_CASE_ATTRIBUTES` constant, use `XmlEncoder::TYPE_CAST_ATTRIBUTES` instead
  * added option to output a UTF-8 BOM in CSV encoder via `CsvEncoder::OUTPUT_UTF8_BOM_KEY` context option
+ * added `ProblemNormalizer` to normalize errors according to the API Problem spec (RFC 7807)
 
 4.3.0
 -----
diff --git a/src/Symfony/Component/Serializer/Normalizer/ProblemNormalizer.php b/src/Symfony/Component/Serializer/Normalizer/ProblemNormalizer.php
new file mode 100644
index 0000000000000..0569c2923bcda
--- /dev/null
+++ b/src/Symfony/Component/Serializer/Normalizer/ProblemNormalizer.php
@@ -0,0 +1,74 @@
+<?php
+
+/*
+ * This file is part of the Symfony package.
+ *
+ * (c) Fabien Potencier <fabien@symfony.com>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace Symfony\Component\Serializer\Normalizer;
+
+use Symfony\Component\ErrorHandler\Exception\FlattenException;
+
+/**
+ * Normalizes errors according to the API Problem spec (RFC 7807).
+ *
+ * @see https://tools.ietf.org/html/rfc7807
+ *
+ * @author Kévin Dunglas <dunglas@gmail.com>
+ * @author Yonel Ceruto <yonelceruto@gmail.com>
+ */
+class ProblemNormalizer implements NormalizerInterface, CacheableSupportsMethodInterface
+{
+    private $debug;
+    private $defaultContext = [
+        'type' => 'https://tools.ietf.org/html/rfc2616#section-10',
+        'title' => 'An error occurred',
+    ];
+
+    public function __construct(bool $debug = false, array $defaultContext = [])
+    {
+        $this->debug = $debug;
+        $this->defaultContext = $defaultContext + $this->defaultContext;
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function normalize($exception, $format = null, array $context = [])
+    {
+        $context += $this->defaultContext;
+
+        $data = [
+            'type' => $context['type'],
+            'title' => $context['title'],
+            'status' => $context['status'] ?? $exception->getStatusCode(),
+            'detail' => $this->debug ? $exception->getMessage() : $exception->getStatusText(),
+        ];
+        if ($this->debug) {
+            $data['class'] = $exception->getClass();
+            $data['trace'] = $exception->getTrace();
+        }
+
+        return $data;
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function supportsNormalization($data, $format = null): bool
+    {
+        return $data instanceof FlattenException;
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function hasCacheableSupportsMethod(): bool
+    {
+        return true;
+    }
+}
diff --git a/src/Symfony/Component/Serializer/Tests/Normalizer/ProblemNormalizerTest.php b/src/Symfony/Component/Serializer/Tests/Normalizer/ProblemNormalizerTest.php
new file mode 100644
index 0000000000000..4a754ac5b7d6c
--- /dev/null
+++ b/src/Symfony/Component/Serializer/Tests/Normalizer/ProblemNormalizerTest.php
@@ -0,0 +1,48 @@
+<?php
+
+/*
+ * This file is part of the Symfony package.
+ *
+ * (c) Fabien Potencier <fabien@symfony.com>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace Symfony\Component\Serializer\Tests\Normalizer;
+
+use PHPUnit\Framework\TestCase;
+use Symfony\Component\ErrorHandler\Exception\FlattenException;
+use Symfony\Component\Serializer\Normalizer\ProblemNormalizer;
+
+class ProblemNormalizerTest extends TestCase
+{
+    /**
+     * @var ProblemNormalizer
+     */
+    private $normalizer;
+
+    protected function setUp(): void
+    {
+        $this->normalizer = new ProblemNormalizer(false);
+    }
+
+    public function testSupportNormalization()
+    {
+        $this->assertTrue($this->normalizer->supportsNormalization(FlattenException::createFromThrowable(new \Exception())));
+        $this->assertFalse($this->normalizer->supportsNormalization(new \Exception()));
+        $this->assertFalse($this->normalizer->supportsNormalization(new \stdClass()));
+    }
+
+    public function testNormalize()
+    {
+        $expected = [
+            'type' => 'https://tools.ietf.org/html/rfc2616#section-10',
+            'title' => 'An error occurred',
+            'status' => 500,
+            'detail' => 'Internal Server Error',
+        ];
+
+        $this->assertSame($expected, $this->normalizer->normalize(FlattenException::createFromThrowable(new \RuntimeException('Error'))));
+    }
+}
diff --git a/src/Symfony/Component/Serializer/composer.json b/src/Symfony/Component/Serializer/composer.json
index 45c185a364e7e..cf48812e1ebf0 100644
--- a/src/Symfony/Component/Serializer/composer.json
+++ b/src/Symfony/Component/Serializer/composer.json
@@ -20,17 +20,18 @@
         "symfony/polyfill-ctype": "~1.8"
     },
     "require-dev": {
-        "symfony/yaml": "^3.4|^4.0|^5.0",
+        "doctrine/annotations": "~1.0",
+        "doctrine/cache": "~1.0",
+        "phpdocumentor/reflection-docblock": "^3.2|^4.0",
+        "symfony/cache": "^3.4|^4.0|^5.0",
         "symfony/config": "^3.4|^4.0|^5.0",
-        "symfony/property-access": "^3.4|^4.0|^5.0",
+        "symfony/dependency-injection": "^3.4|^4.0|^5.0",
+        "symfony/error-handler": "^4.4|^5.0",
         "symfony/http-foundation": "^3.4|^4.0|^5.0",
-        "symfony/cache": "^3.4|^4.0|^5.0",
+        "symfony/property-access": "^3.4|^4.0|^5.0",
         "symfony/property-info": "^3.4.13|~4.0|^5.0",
         "symfony/validator": "^3.4|^4.0|^5.0",
-        "doctrine/annotations": "~1.0",
-        "symfony/dependency-injection": "^3.4|^4.0|^5.0",
-        "doctrine/cache": "~1.0",
-        "phpdocumentor/reflection-docblock": "^3.0|^4.0"
+        "symfony/yaml": "^3.4|^4.0|^5.0"
     },
     "conflict": {
         "phpdocumentor/type-resolver": "<0.2.1",