Session Handoff [python-contract]: Python Gate Behavior Edge Cases on Develop, Promotion #1943 Ready

[ptr727]

This round settled #1936's behavior-changing edge cases with the maintainer's decision on each item. The work landed on develop in #1942 and #1944. Promotion #1943 is ready but not merged.

Next steps, in priority order

Re-read each issue and pull request rather than trusting these summaries.

1. Merge promotion Promote develop to main: Settle the Python Gate's Behavior-Changing Edge Cases #1943 and release. It meets every Merge Gate item except the maintainer's go-ahead. Its head at handoff was 29a9690a, so re-read it before merging. Done looks like: main carries Settle the Python Gate's Behavior-Changing Edge Cases From #1936 #1942 and Pluralize the Audit's Extra-Caller Finding for Several Jobs #1944, Decide the Python Directory Gate's Behavior-Changing Edge Cases #1936 is closed, and a release is dispatched if the maintainer wants one.
2. PlexCleaner adopts the gate. This is unchanged from earlier links. It is first in the adoption order the maintainer set on Gate Every Repository's Python on Its Code, Not on Its Config #1800, and it happens in PlexCleaner's own session. Bump the validator pin to the release carrying Settle the Python Gate's Behavior-Changing Edge Cases From #1936 #1942 or later, and pass python-directories: RegressionTests on both callers. RegressionTests/ needs a tests/ suite and a mypy config first. The root-config fallback from Settle the Python Gate's Behavior-Changing Edge Cases From #1936 #1942 means its mypy config can live at the root. Done looks like: CI is green and the (python.directories.declared) driftNote is deleted.
3. Python Build Profile's Pyright Rule Disagrees With the Gate's Mypy-Only Acceptance #1941, the build profile's pyright rule versus the gate. It waits on the maintainer's decision.
4. Remaining deferred edge cases: Read a with: Input Past a Deeper-Indented Comment in the Audit #1916 and Count a setup.cfg [mypy] Section as a Declared Directory's Type Checker #1915, then configure.sh Resolves a Registry Entry by Name Rather Than by owner/repo Identity #1894 and Three Test Harnesses Build a Stand-In PATH With an Empty Fallback When PATH Is Unset #1862.

External blockers

• Promote develop to main: Settle the Python Gate's Behavior-Changing Edge Cases #1943 merge and release: the maintainer's explicit go-ahead.
• Python Build Profile's Pyright Rule Disagrees With the Gate's Mypy-Only Acceptance #1941: the maintainer's decision.
• Each adoption runs in another repository's session.

Internal dependencies

• The PlexCleaner bump should target the release that carries Settle the Python Gate's Behavior-Changing Edge Cases From #1936 #1942, which means Promote develop to main: Settle the Python Gate's Behavior-Changing Edge Cases #1943 has to merge and a release has to be dispatched first.
• Read a with: Input Past a Deeper-Indented Comment in the Audit #1916 and Count a setup.cfg [mypy] Section as a Declared Directory's Type Checker #1915 touch the audit and the checker lookup that Settle the Python Gate's Behavior-Changing Edge Cases From #1936 #1942 just changed. Re-read validate-task.yml's type-check step and spec/audit.py's python_directories_caller_findings before starting them.

State

Re-derive each of these at resume.

• main: unchanged from the previous link.
• develop: carries Settle the Python Gate's Behavior-Changing Edge Cases From #1936 #1942 (cae0c12a) and Pluralize the Audit's Extra-Caller Finding for Several Jobs #1944 (29a9690a).
• Open PRs: Promote develop to main: Settle the Python Gate's Behavior-Changing Edge Cases #1943, develop into main.
• Worktrees: this round's two worktrees and their branches are removed, locally and on the remote. The base clone is on develop and clean.
• Other tracks: default (Session Handoff [default]: Audit Report Authorship Settled, Unattended Loop Live-Tested, 2.0.680 Released #1828).

The parked decision queue

One open issue carries decision: #1941. It was presented to the maintainer at handoff.

What the last round did

• Recorded the maintainer's decisions on Decide the Python Directory Gate's Behavior-Changing Edge Cases #1936's seven items, as a comment on that issue. Item 4 stays as it is.
• Settle the Python Gate's Behavior-Changing Edge Cases From #1936 #1942 implemented items 1, 2, 3, 5, 6, and 7.
• Pluralize the Audit's Extra-Caller Finding for Several Jobs #1944 fixed the singular wording of the extra-caller finding, which Copilot raised on Promote develop to main: Settle the Python Gate's Behavior-Changing Edge Cases #1943.
• Filed Python Build Profile's Pyright Rule Disagrees With the Gate's Mypy-Only Acceptance #1941, a pre-existing gap the local review found.
• Declined one Promote develop to main: Settle the Python Gate's Behavior-Changing Edge Cases #1943 finding with a mypy probe: that setup.cfg should take precedence over pyproject.toml.

What not to repeat

• Waving off a user-visible message as "cosmetic". The local reviewer called the singular grammar with two jobs cosmetic. Copilot then raised it on the promotion PR, which cost a whole feature, develop, and promotion cycle. Fix a wrong message string when the local pass sees it.
• A pin grep that ignores which file mypy loads. The first pin check grepped python_version in all four config files and every section. Two review rounds went to scoping it to the one file mypy loads, then to configparser's : form. Mirror the tool's own lookup order and syntax from the start.
• A mutant hidden by a coincident finding. The first flow-mapping selftest case used a registry naming Tools, so the misread still produced a finding and a mutant removing the check survived. Choose fixtures where the defect is the only possible source of the expected result.

New learnings

• mypy's config precedence is mypy.ini, .mypy.ini, pyproject.toml with [tool.mypy], then setup.cfg with [mypy]. This was probed on mypy 2.3.1 and recorded in the Promote develop to main: Settle the Python Gate's Behavior-Changing Edge Cases #1943 decline, and the step's pins_python_version() encodes it.

[ptr727]

Answers given at handoff:

• Promote develop to main: Settle the Python Gate's Behavior-Changing Edge Cases #1943: merge and release, and this session is doing it now.
• Python Build Profile's Pyright Rule Disagrees With the Gate's Mypy-Only Acceptance #1941: allow mypy-only for a build directory. The answer is recorded on the issue, and its decision label is removed. The spec change is still to do, so it stays in next steps.

The parked decision queue now holds 0 issues.

[ptr727]

Next step 1 is done: #1943 is merged to main as 9040965 and released as 2.0.718 (publish-release run 36360084736 succeeded). #1936 is closed. This machine's skills are refreshed from main. PlexCleaner's adoption (next step 2) can now pin 2.0.718 or later. #1941's spec change, allowing mypy-only for build directories as the maintainer decided, is still open.

[ptr727]

Continued in #2008, round 7 on track python-contract.