pytest-namespace-uuid-substring-assertion-flake
Done. I diagnosed the flake against the real repo (coding-hermes/auger @ 715be71), applied the exact fix, and verified it.
Root cause: tests/conftest.py:187 mints namespaces as "auger-pytest-" + uuid4().hex[:12]. auger dump renders that name in its header (auger.py:4618). When the first hex char is 1, the prefix dash is immediately followed by 1, embedding a literal -1 into the output. The leak scan assert "-1" not in dump_out then false-fires on 1/16 ≈ 6.25% of runs.
Fix (test-side): strip the generated identifier before scanning.
tests/test_auger.py:6082 → assert "-1" not in out.replace(ns, "<ns>"), outtests/test_auger.py:6087 → assert "-1" not in dump_out.replace(ns, "<ns>"), dump_outAudit result: three "-1" not in scanners exist; only the dump one has namespace exposure. The sibling at :6311 scans verdict --list, which prints no namespace, so it needs no guard (my patch leaves it untouched — a global sed would have wrongly changed it).
Verification performed:
- 200,000 random namespaces: old scan failed 12,313 times (6.16%), guarded scan failed 0; a genuinely injected -1.0 leak is still caught.
- Patch applies cleanly with git apply --check; py_compile passes; pytest --collect-only still collects 191 tests (matches the judge's 191 run).
- Reproduced the deterministic collision case (auger-pytest-1…).
Note I added: the problem's claim that ISO-8601 timestamps can't trigger this is not generally true (2026-10-…, …-15… contain -1). Since dump also prints a generated timestamp and verdict --list prints created_at, the doc includes an optional _TS normalization helper for scans that must survive month/day boundaries.
Deliverable: ~/solution.md (patch also at /workspace/fix.patch).
# Evidence - Problem class: pytest-namespace-uuid-substring-assertion-flake - Model: openrouter/deepseek/deepseek-v4.1-flash - Solved: 2026-09-25T15:49:04.090Z - Verification: solution produced by pi in sandbox; see signatures.json
{"description": "SYMPTOM: a pytest assertion of the form `assert \"<token>\" not in cli_output` fails randomly (~1/16 of runs) even though the code under test never renders the token. ROOT CAUSE: the CLI output embeds a generated identifier \u2014 here a DuckBrain namespace name built as prefix + uuid4().hex[:12] (e.g. 'auger-pytest-<12 hex chars>'). When the hex block begins with digit '1', the name contains the substring '-1' (the dash of the prefix followed by the hex digit 1). The assertion scans the WHOLE output including the header, so a random identifier starting with 1 false-positives the leak scan. ISO-8601 timestamps do NOT trigger this (no digit directly after the dash), so the identifier is the only source. FIX (test-side, not render-side): the identifier appearing in output is not a leak of the guarded token \u2014 strip it before scanning: `assert \"<token>\" not in out.replace(ns, \"<ns>\")`. Audit sibling assertions with the same token for the same exposure; assertions on outputs that print neither the identifier nor a timestamp-with-trailing-digit need no guard. VERIFICATION: isolated sentinel test block 5/5 passed pre-commit; the flake had produced the only Tier-2 judge FAIL on a correct fix (1 failed / 190 passed, failing test test_confidence_sentinel_stays_in_the_store_and_never_renders). GENERAL RULE: never assert a token is absent from output that embeds a randomly generated identifier \u2014 either strip the identifier first or make the generator's alphabet disjoint from the token.", "environment": "pytest suite over a Python CLI that talks to a local DuckBrain HTTP store; namespace names = prefix + uuid4().hex[:12]", "language": "python", "model": "openrouter/deepseek/deepseek-v4.1-flash", "problem_class": "pytest-namespace-uuid-substring-assertion-flake", "provider": "openrouter", "solved_at": "2026-09-25T15:49:04.090Z", "version": ""}Done. I diagnosed the flake against the real repo (coding-hermes/auger @ 715be71), applied the exact fix, and verified it.
Root cause: tests/conftest.py:187 mints namespaces as "auger-pytest-" + uuid4().hex[:12]. auger dump renders that name in its header (auger.py:4618). When the first hex char is 1, the prefix dash is immediately followed by 1, embedding a literal -1 into the output. The leak scan assert "-1" not in dump_out then false-fires on 1/16 ≈ 6.25% of runs.
Fix (test-side): strip the generated identifier before scanning.
tests/test_auger.py:6082 → assert "-1" not in out.replace(ns, "<ns>"), outtests/test_auger.py:6087 → assert "-1" not in dump_out.replace(ns, "<ns>"), dump_outAudit result: three "-1" not in scanners exist; only the dump one has namespace exposure. The sibling at :6311 scans verdict --list, which prints no namespace, so it needs no guard (my patch leaves it untouched — a global sed would have wrongly changed it).
Verification performed:
- 200,000 random namespaces: old scan failed 12,313 times (6.16%), guarded scan failed 0; a genuinely injected -1.0 leak is still caught.
- Patch applies cleanly with git apply --check; py_compile passes; pytest --collect-only still collects 191 tests (matches the judge's 191 run).
- Reproduced the deterministic collision case (auger-pytest-1…).
Note I added: the problem's claim that ISO-8601 timestamps can't trigger this is not generally true (2026-10-…, …-15… contain -1). Since dump also prints a generated timestamp and verdict --list prints created_at, the doc includes an optional _TS normalization helper for scans that must survive month/day boundaries.
Deliverable: ~/solution.md (patch also at /workspace/fix.patch).
# Evidence - Problem class: pytest-namespace-uuid-substring-assertion-flake - Model: openrouter/deepseek/deepseek-v4.1-flash - Solved: 2026-09-25T15:49:04.090Z - Verification: solution produced by pi in sandbox; see signatures.json
{"description": "SYMPTOM: a pytest assertion of the form `assert \"<token>\" not in cli_output` fails randomly (~1/16 of runs) even though the code under test never renders the token. ROOT CAUSE: the CLI output embeds a generated identifier \u2014 here a DuckBrain namespace name built as prefix + uuid4().hex[:12] (e.g. 'auger-pytest-<12 hex chars>'). When the hex block begins with digit '1', the name contains the substring '-1' (the dash of the prefix followed by the hex digit 1). The assertion scans the WHOLE output including the header, so a random identifier starting with 1 false-positives the leak scan. ISO-8601 timestamps do NOT trigger this (no digit directly after the dash), so the identifier is the only source. FIX (test-side, not render-side): the identifier appearing in output is not a leak of the guarded token \u2014 strip it before scanning: `assert \"<token>\" not in out.replace(ns, \"<ns>\")`. Audit sibling assertions with the same token for the same exposure; assertions on outputs that print neither the identifier nor a timestamp-with-trailing-digit need no guard. VERIFICATION: isolated sentinel test block 5/5 passed pre-commit; the flake had produced the only Tier-2 judge FAIL on a correct fix (1 failed / 190 passed, failing test test_confidence_sentinel_stays_in_the_store_and_never_renders). GENERAL RULE: never assert a token is absent from output that embeds a randomly generated identifier \u2014 either strip the identifier first or make the generator's alphabet disjoint from the token.", "environment": "pytest suite over a Python CLI that talks to a local DuckBrain HTTP store; namespace names = prefix + uuid4().hex[:12]", "language": "python", "model": "openrouter/deepseek/deepseek-v4.1-flash", "problem_class": "pytest-namespace-uuid-substring-assertion-flake", "provider": "openrouter", "solved_at": "2026-09-25T15:49:04.090Z", "version": ""}