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kind: infra workflow: v1

Test-order contamination: a later-sorting module registers wildchat_prefix_real545 into CONTEXTS, failing test_conv_context_is_wildchat_family in multi-file runs

Goal

Find and fix the collection/import-time registry contamination that makes tests/test_issue1090_fu3_dispatcher.py::test_conv_context_is_wildchat_family FAIL in large multi-file pytest runs while passing (a) alone, and (b) in the single-file pristine-main oracle.

Evidence (from #2059's Step 9c gate, 2026-08-10)

• In a 239-file Step 9c gate run (worktree issue-2059, all relevant files byte-identical to origin/main), the test failed with AssertionError: importing fu3_cells must not register the conv prefix (r2 concern) — 'wildchat_prefix_real545' was ALREADY in CONTEXTS at assert time.
• The same file run alone in the same tree: 8 passed.
• Single-file pristine-main oracle: passed → step9c_baseline.py compare classified the node NEW (fail-closed).
• The paired-prefix oracle (34 prefix files) did NOT reproduce it → ordering_suspect empty. This matches the documented residual blind class in .claude/skills/issue/SKILL.md Step 9c 1d: contamination from a file sorting AFTER the candidate is present in the gate process but absent from any prefix replay.
• #2059's diff (backends routing, runpod tests, docs) imports none of the fu3/CONTEXTS machinery; the gate PASSed via manual provenance-override (see #2059 epm:test-verdict).

Suggested approach

Bisect the contaminator: run tests/test_issue1090_fu3_dispatcher.py together with suffix subsets of the gate's file list (files sorting after it alphabetically, e.g. the later test_issue1090_fu4/fu6, test_issue1776_* families) until the failure reproduces; then either (a) make the offending module stop registering the conv context at import time, or (b) make the test hermetic (snapshot/restore the CONTEXTS registry or assert against a freshly-imported module). Also consider whether the Step 9c paired oracle could gain a SUFFIX-replay arm to close the documented blind class mechanically.

Provenance

Filed by the #2059 session after its Step 9c gate; originating evidence at tasks//2059/events.jsonl (epm:test-verdict marker, 2026-08-10T09:25Z) and /tmp/step9c-compare-issue-2059.json (session-local).