Python: Crash Fixes Sweep the Backports
A cluster of correctness and crash fixes landed across CPython this week, all being methodically backported to 3.13, 3.14, and 3.15, alongside a wave of iOS build fixes from the same contributor.
Duration: PT2M57S
Episode overview
This episode is a short developer briefing from Python.
It explains recent repository work in plain language.
- Show: Python
- Published: 2026-08-22T13:07:35Z
- Audio duration: PT2M57S
Transcript excerpt
This excerpt keeps the crawler page concise. Listen to the episode or use the RSS feed for the full update.
Good day, it's August 22nd, and this is Python.
The dominant pattern this cycle isn't new features, it's crash hardening and the disciplined backport work that follows it. When a fix lands on main, it's now reliably chased down into three older branches within hours.
Start with concurrency. Neil Schemenauer's fix in PR 153462 closes a race in os dot scandir, where one thread could be reading a directory while another closed it out from under it. That's now serialized with a mutex. A related free-threading fix, PR 155579, plugs a slot leak in thread-state creation on failure…
Second theme: attribute handling in C code. Serhiy Storchaka's PR 156107 added systematic tests for setting and deleting attributes defined with PyMemberDef and PyGetSetDef — areas that turned out to be under-tested. That effort immediately paid off: it surfaced a real crash, fixed in PR 156190, where deleting frame…
Third theme: platform build fixes, all from Clément Péron, all iOS-specific. PR 156116 fixes simulator builds picking up the wrong device deployment flag, and PR 156113 adds a fallback when the ObjC runtime library can't be located by name. Both were merged to main and immediately backported to…
Worth…
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