test(spread): add core26 venv/bin/python reproducer for uv dispatch script bug

Metadata

Project: charmcraft
Number: #2789
Type: pull request
State: open
Author: copilot-swe-agent
Labels: —
Created: 2026-07-15 04:26 PM UTC
Updated: 2026-08-13 12:34 AM UTC
Closed: —

Current evaluation

Test-only spread change adding a core26 reproducer: requires venv/bin/python in the uv charm payload and runs `venv/bin/python -c "import ops"` in the task. 2 slow-test jobs fail, 1 review comment unresolved, no reviewers.

Suggested action: keep open

Reason: The change is a deliberate reproducer for the open bug in charmcraft#2788 ("uv plugin fails on core26: dispatch script uses system Python instead of venv"), so the new `expected_files.txt` entry and `import ops` check will fail until the product-side fix lands; CI is also red (test / Slow tests (ubuntu-24.04, 3.10 and 3.12)) with 2 checks still pending and 1 unresolved review comment that has sat for 50 days with no author response. Code-file inspection was unavailable (no pinned SHA for the repo), so the exact spread-test gating could not be verified, which caps confidence; the failing slow tests may be pre-existing flakiness rather than caused by this diff.

Evaluated by: mr-cal-bot

Impact: 28 Quick Win: 7 Complexity: 22 Confidence: 66 Actionability: 32

Issue body

On core26, craft-parts removes `python*` symlinks from `venv/bin/` and falls back to the system interpreter path. The packed charm lacks `venv/bin/python`, so the dispatch script creates `ln -s $(which python3) venv/bin/python` at runtime — pointing to a Python with no `ops` installed, causing `ModuleNotFoundError`. ## Changes - **`ubuntu-26.04/charm/uv/expected_files.txt`**: Add `venv/bin/python` to the required file list. The `unzip -qql` check already fails the test if the entry is absent from the charm archive, directly reproducing the missing-symlink scenario. - **`ubuntu-26.04/charm/task.yaml`**: When `venv/bin/python` is in `expected_files.txt`, extract the charm to a temp dir and run: ```sh "$tmpdir/venv/bin/python" -c "import ops" ``` This catches two failure modes: the symlink being absent entirely, or present but pointing to a system Python that lacks venv packages. The check is gated on `expected_files.txt` content so it only fires for the uv charm, not the platforms charm.

Evaluation history

Date	Model	Scores	Action	Summary
2026-10-02 08:29 PM UTC	stealth/space-bunny-alpha	Impact: 28 Quick Win: 7 Complexity: 22 Confidence: 66 Actionability: 32	keep open	Test-only spread change adding a core26 reproducer: requires venv/bin/python in the uv charm payload and runs `venv/bin/python -c "import ops"` in the task. 2 slow-test jobs fail, 1 review comment unresolved, no reviewers.
2026-10-02 08:28 PM UTC	stealth/space-bunny-alpha	Impact: 32 Quick Win: 7 Complexity: 22 Confidence: 58 Actionability: 30	needs review	Test-only spread PR: adds venv/bin/python to the core26 uv charm expected_files.txt and an extraction + "import ops" check in task.yaml, reproducing the uv dispatch symlink bug. No reviewers, 1 unresolved comment, 2 slow-test checks failing.
2026-09-24 09:18 PM UTC	stealth/space-bunny-alpha	Impact: 22 Quick Win: 6 Complexity: 28 Confidence: 82 Actionability: 38	keep open	Adds core26 spread checks for the uv charm's venv/bin/python symlink and importability; two slow-test jobs fail, two checks are pending, and one review comment is unresolved.
2026-09-05 05:32 PM UTC	qwen3.6-35b-a3b-mtp-q6	Impact: 35 Quick Win: 30 Staleness: 65 Complexity: 15 Confidence: 45	needs review	Adds a spread test reproducing core26 venv/bin/python symlink removal bug; 52 days old, 0 reviewers, slow CI tests failing
2026-08-13 12:41 AM UTC	qwen/qwen3.6-35b-a3b	Staleness: 25 Complexity: 10 Confidence: 85	needs review	Adds a spread test to reproduce a core26 charm dispatch bug where missing venv/bin/python symlinks cause ModuleNotFoundError. Currently pending review with one unresolved comment and failing slow CI jobs.
2026-07-22 02:48 PM UTC	qwen/qwen3.6-35b-a3b	Staleness: 15 Complexity: 10 Confidence: 85	needs review	Adds a spread test to reproduce a core26 bug where craft-parts removes venv/python symlinks, causing dispatch script failures. Currently pending maintainer review with passing CI.
2026-07-15 08:03 PM UTC	qwen3.6-35b-a3b-mtp-q6	Staleness: 5 Complexity: 15 Confidence: 85	needs review	Adds a spread test to reproduce a core26 charm dispatch bug where craft-parts removes venv/bin/python symlinks, causing ModuleNotFoundError. Currently unreviewed with no comments.

Update history

Date	Change
2026-08-13 12:34 AM UTC	updated

Related work

Related To: charmcraft#2788 (confidence 88%)
Open issue describing the exact core26 uv charm failure this PR reproduces (payload symlink removed, dispatch links venv/bin/python to system Python, ModuleNotFoundError: ops); the PR only adds a test, so the fix is still needed.

Related issues

No related issues found above the similarity threshold.