Fix crash on mypy imports when using --extension-pkg-allow-list=mypy

.gitignore

@@ -27,3 +27,4 @@ build-stamp
 .pytest_cache/
 .mypy_cache/
 .benchmarks/
+venv/

pylint/checkers/imports.py

@@ -1033,6 +1033,26 @@
 
             dotted_modname = get_import_name(importnode, modname)
             self.add_message("import-error", args=repr(dotted_modname), node=importnode)
+        except AttributeError as e:
+            # Handle mypyc compiled modules that may not have __dict__
+            if "__dict__" in str(e):
+                if not self.linter.is_message_enabled("import-error"):
+                    return None
+                if _ignore_import_failure(importnode, modname, self._ignored_modules):
+                    return None
+                if (
+                    not self.linter.config.analyse_fallback_blocks
+                    and is_from_fallback_block(importnode)
+                ):
+                    return None
+
+                dotted_modname = get_import_name(importnode, modname)
+                self.add_message(
+                    "import-error", args=repr(dotted_modname), node=importnode
+                )
+            else:
+                # Re-raise other AttributeErrors
+                raise astroid.AstroidError from e
         except Exception as e:  # pragma: no cover
             raise astroid.AstroidError from e
         return None

tests/functional/i/import_mypy_extension.py

@@ -0,0 +1,12 @@
+"""Test for mypy extension package import crash regression.
+
+This reproduces the crash described in issue #10223 where importing
+mypy modules with --extension-pkg-allow-list=mypy caused an AttributeError
+crash due to mypyc-compiled objects not having __dict__ attributes.
+
+The fix ensures this generates an import-error message instead of crashing.
+"""
+# pylint: disable=unused-import
+
+# This should not crash when using --extension-pkg-allow-list=mypy
+import mypy.build  # [import-error]

tests/functional/i/import_mypy_extension.rc

@@ -0,0 +1,5 @@
+[Messages Control]
+disable=C,R,W
+
+[TYPECHECK]
+extension-pkg-allow-list=mypy

tests/functional/i/import_mypy_extension.txt

@@ -0,0 +1 @@
+import-error:12:0:12:17::Unable to import 'mypy.build':UNDEFINED