> [!NOTE] > This PR was created by [GitHub Copilot CLI](https://github.com/github/copilot-cli) (an AI agent), on behalf of @lengau. ## Summary Fixes the integration test failures seen in [run 31630147223](https://github.com/canonical/charmcraft/actions/runs/31630147223/job/94226573094?pr=2818): ``` FileExistsError: [Errno 17] File exists: '.../project/src' ``` Newer versions of the `uv` CLI now scaffold a `src/<package>/__init__.py` layout by default during `uv init --no-workspace`, so the `uv_project` pytest fixture's unconditional `source_dir.mkdir()` call raised because the directory already existed. ## Fix The fixture now removes any `uv init`-scaffolded `src/` directory before recreating it, so the source tree only ever contains what the test intends (just `charm.py`), rather than silently leaving an unrelated scaffolded package (`src/test_charm/__init__.py`) that would otherwise get built, installed, and staged alongside it. ## Review Had 5 different models (Claude Opus 4.5, GPT-5.4, Gemini 3.1 Pro, Grok 4.5, Kimi K3) independently review the change. Gemini 3.1 Pro flagged that a simpler `exist_ok=True` fix would leave the scaffolded package in place; addressed by removing the directory first instead. ## Testing - `ruff check tests/integration/parts/plugins/test_uv.py` passes. - Ran the test locally — fixture setup succeeds with no `FileExistsError` (only remaining local failure is an unrelated sandbox limitation: no privileged apt backend available here, not present on CI runners).