Print warning when mkdir fails instead of silently ignoring the error

hintron · hintron · commit 8837d9ad9788 · 2024-09-14T00:23:06.000-07:00
For example, a user could have no more disk space, causing mkdir to fail,
but not realize it because the error is silently discarded, and the
subsequent warning would not indicate the actual issue.
diff --git a/lib/matplotlib/__init__.py b/lib/matplotlib/__init__.py
@@ -530,26 +530,27 @@ def _get_config_or_cache_dir(xdg_base_getter):
     configdir = configdir.resolve()
     try:
         configdir.mkdir(parents=True, exist_ok=True)
-    except OSError:
-        pass
+    except OSError as exc:
+        _log.warning("mkdir -p failed for path %s: %s", configdir, exc)
     else:
         if os.access(str(configdir), os.W_OK) and configdir.is_dir():
             return str(configdir)
+        _log.warning("%s is not a writable directory", configdir)
     # If the config or cache directory cannot be created or is not a writable
     # directory, create a temporary one.
     try:
         tmpdir = tempfile.mkdtemp(prefix="matplotlib-")
     except OSError as exc:
         raise OSError(
-            f"Matplotlib requires access to a writable cache directory, but the "
-            f"default path ({configdir}) is not a writable directory, and a temporary "
+            f"Matplotlib requires access to a writable cache directory, but there "
+            f"was an issue with the default path ({configdir}), and a temporary "
             f"directory could not be created; set the MPLCONFIGDIR environment "
             f"variable to a writable directory") from exc
     os.environ["MPLCONFIGDIR"] = tmpdir
     atexit.register(shutil.rmtree, tmpdir)
     _log.warning(
-        "Matplotlib created a temporary cache directory at %s because the default path "
-        "(%s) is not a writable directory; it is highly recommended to set the "
+        "Matplotlib created a temporary cache directory at %s because there was "
+        "an issue with the default path (%s); it is highly recommended to set the "
         "MPLCONFIGDIR environment variable to a writable directory, in particular to "
         "speed up the import of Matplotlib and to better support multiprocessing.",
         tmpdir, configdir)
