Fix an async job pool (retries, deadlock, error capture) with hidden tests

A small Python async job pool with four reported problems: failed jobs crash the run, the pool can hang after failures, retry counts are off, and reuse breaks. The agent must read the README contract, fix the library, and add tests; hidden tests check retry semantics, the deadlock on failure, and that cancellation is not swallowed. Original benchmark task written for usecaserank.com (not based on a specific public post). Headless, offline run on a reproducible fixture. Each run's notes say how its cost was measured (estimates are marked).

Success criteria: 1. Hidden test file is copied into tests/ and the full suite (visible + hidden + agent tests) runs with pytest; exit code must be 0 (120 s timeout). 2. Hidden tests check: retries means EXTRA attempts (retries=2 -> up to 3 attempts) with exact stats {ok, failed, attempts}; no deadlock/hang after several failing jobs; concurrency never exceeds the configured bound (and reaches it); the pool can be reused across separate asyncio.run() calls; asyncio.CancelledError propagates instead of being swallowed as a failure. 3. Visible tests must still pass: results returned in job order; failed jobs appear as exception instances and run() never raises. 4. The repo's tests/ must contain at least 4 test functions in total (i.e. the agent added at least 2).

Best model for this task so far: Claude Haiku 5.5 (effort default (no --effort flag) · thinking on) (success, $0.0090, 40s).

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All runs (5)

100% pass rate across 5 eligible runs: 5 pass, 0 partial, 0 fail. Partial and failed runs are listed below with everything else.ⓘ