Try to prevent a PermissionError on Windows

godlygeek · chris-eibl · web-flow · commit 09adb2b9b0aa · 2025-04-18T12:34:37.000-04:00
If `NamedTemporaryFile.__exit__` tries to delete the connect script
before the remote process has closed it, a `PermissionError` is raised
on Windows. Unfortunately there is no synchronization that we can use to
ensure that the file is closed before we try to delete it. This makes
the race less likely to occur by making the `with` block contain more
code, so that more time passes before we attempt to delete the file.

Co-authored-by: Chris Eibl &lt;138194463+chris-eibl@users.noreply.github.com&gt;
diff --git a/Lib/pdb.py b/Lib/pdb.py
@@ -3044,31 +3044,31 @@ def attach(pid):
     with closing(socket.create_server(("localhost", 0))) as server:
         port = server.getsockname()[1]
 
-        with tempfile.NamedTemporaryFile("w", delete_on_close=False) as script:
-            script.write(
+        with tempfile.NamedTemporaryFile("w", delete_on_close=False) as connect_script:
+            connect_script.write(
                 f'import pdb, sys\n'
                 f'pdb._connect("localhost", {port}, sys._getframe().f_back)\n'
             )
-            script.close()
-            sys.remote_exec(pid, script.name)
+            connect_script.close()
+            sys.remote_exec(pid, connect_script.name)
 
             # TODO Add a timeout? Or don't bother since the user can ^C?
             client_sock, _ = server.accept()
 
-    with closing(client_sock):
-        sockfile = client_sock.makefile("rwb")
+            with closing(client_sock):
+                sockfile = client_sock.makefile("rwb")
 
-    with closing(sockfile):
-        with tempfile.NamedTemporaryFile("w", delete_on_close=False) as script:
-            script.write(
-                'import pdb, sys\n'
-                'if inst := pdb.Pdb._last_pdb_instance:\n'
-                '    inst.set_step()\n'
-                '    inst.set_trace(sys._getframe(1))\n'
-            )
-            script.close()
+            with closing(sockfile):
+                with tempfile.NamedTemporaryFile("w", delete_on_close=False) as interrupt_script:
+                    interrupt_script.write(
+                        'import pdb, sys\n'
+                        'if inst := pdb.Pdb._last_pdb_instance:\n'
+                        '    inst.set_step()\n'
+                        '    inst.set_trace(sys._getframe(1))\n'
+                    )
+                    interrupt_script.close()
 
-            _PdbClient(pid, sockfile, script.name).cmdloop()
+                    _PdbClient(pid, sockfile, interrupt_script.name).cmdloop()
 
 
 # Post-Mortem interface
