Merge pull request #1472 from pallets/debugger-pin

ignore getuser KeyError for debugger pin

CHANGES.rst

@@ -92,6 +92,9 @@ Unreleased
     incorrectly classify some frames. (:pr:`1421`)
 -   Clicking the error message at the top of the interactive debugger
     will jump down to the bottom of the traceback. (:pr:`1422`)
+-   When generating a PIN, the debugger will ignore a ``KeyError``
+    raised when the current UID doesn't have an associated username,
+    which can happen in Docker. (:issue:`1471`)
 -   :class:`~exceptions.BadRequestKeyError` adds the ``KeyError``
     message to the description, making it clearer what caused the 400
     error. Frameworks like Flask can omit this information in production

src/werkzeug/debug/__init__.py

@@ -159,10 +159,11 @@ def get_pin_and_cookie_name(app):
     modname = getattr(app, "__module__", getattr(app.__class__, "__module__"))
 
     try:
-        # `getpass.getuser()` imports the `pwd` module,
-        # which does not exist in the Google App Engine sandbox.
+        # getuser imports the pwd module, which does not exist in Google
+        # App Engine. It may also raise a KeyError if the UID does not
+        # have a username, such as in Docker.
         username = getpass.getuser()
-    except ImportError:
+    except (ImportError, KeyError):
         username = None
 
     mod = sys.modules.get(modname)