An Async Analyzer Finds 457 Confirmed Python Bugs

Python's asynchronous failures can depend on which event happens first, whether two operations touch the same object and what continues after cancellation. AegisAsync models those relationships in an Async Event Transition Graph, then symbolically simulates bounded paths and cancellation at await points. On a 180-risk benchmark, its authors report finding every labeled issue with no false positives across CPython 3.10 through 3.14. A review of 910 candidates from 2,500 PyPI package versions confirmed 457 unique bugs; 166 proof-of-concept programs reproduced findings, 157 reports went to developers and 16 had been confirmed and fixed by submission. Those rates describe the evaluated packages and review process, not every asynchronous Python program. The important advance is the evidence trail: each candidate includes a witness connecting ordering and state across calls, turning a timing-sensitive suspicion into something maintainers can reproduce.