1. Create a Dart package with Flutter SDK as a dependency.
2. Set Dart Code debug option to 'debug my code + packages + SDK'.
3. Run a test that fails an assertion.

The assertion stack frame should appear in the source view.

The assertion appears as a file in a new VSCode tab titled errors_patch.dart with the following content:

Could not load source 'dart:core-patch/errors_patch.dart': <source not available>.