Python: Crash Fixes Across Async and Memory Internals
This cycle centered on hardening CPython's concurrency and low-level internals, with fixes for crashes in async tasks, thread safety in ordered dictionaries, and stale pointer access in buffered I/O, alongside a rapid revert of a shutdown change that broke leak testing.
Duration: PT2M37S
Episode overview
This episode is a short developer briefing from Python.
It explains recent repository work in plain language.
- Show: Python
- Published: 2026-08-01T13:06:47Z
- Audio duration: PT2M37S
Transcript excerpt
This excerpt keeps the crawler page concise. Listen to the episode or use the RSS feed for the full update.
You're listening to Python, your daily developer briefing for August 1st, 2026.
The clear signal today: a wave of crash and correctness fixes across CPython's concurrency-sensitive code, several of which are already flowing into backport branches.
Start with asyncio. Two separate bugs got fixed this cycle. PR 154798 corrected a traceback loss in asyncio dot Future, where calling result twice would silently strip exception frames after the first call. And PR 154898 fixed an actual interpreter crash in Task dot get underscore context, triggered when a Task…
Thread safety is the second theme. PR 151688, merged and folded into commit 86dab7c, closes a race condition in OrderedDict iterator creation under free-threaded builds — a concurrent clear or update could free linked-list nodes mid-iteration, causing a use-after-free. Related in spirit is PR 155017, still open,…
Encoding internals also saw real attention from Serhiy Storchaka, with three separate PRs — 155018, 155005, and 155008 — tightening how CPython handles Windows code pages, iconv shift states, and error-handler replacement strings during text encoding. These are edge cases, but the kind that cause silent data…
One notable…
Nearby episodes from Python
- Curses Cleanup and Correctness Fixes Dominate the Day
- Hardening the Corners Before 3.15
- Thread Safety and the Great Regex Slowdown Cleanup
- Curses Crashes and a Careful Revert
- Curses, Concurrency, and a Reflog Revert
- Weekly Recap - Memory Safety and Backport Discipline
- Locale Encoding Bugs Take Center Stage
- Memory Safety Sweep Across the Interpreter