Python: Old Bugs, Long Overdue Fixes
This cycle's CPython activity centers on fixing long-dormant correctness bugs — some over fifteen years old — in imaplib, HTTP docs, and HTMLParser, alongside a cluster of free-threading race and memory-safety fixes.
Duration: PT2M48S
Episode overview
This episode is a short developer briefing from Python.
It explains recent repository work in plain language.
- Show: Python
- Published: 2026-07-05T13:05:56Z
- Audio duration: PT2M48S
Transcript excerpt
This excerpt keeps the crawler page concise. Listen to the episode or use the RSS feed for the full update.
Good day, and welcome to Python for July 5th, 2026.
The signal this cycle is old bugs finally getting fixed, and fixed properly across every supported branch.
Start with imaplib. Serhiy Storchaka's PR 152703 restores argument quoting that was silently disabled when imaplib was ported to Python 3 — a bug dating back to bpo-1210 and bpo-9638. Commands with a space in a mailbox name have failed quietly since Python 3.0. The fix now follows RFC 3501 grammar and has already…
Same pattern with HTMLParser: PR 153031 fixes quadratic performance when feeding data incrementally — a long-standing scaling trap for anyone parsing HTML in chunks — and it's been backported all the way down to 3.10, the widest backport window we've seen.
Second theme: free-threading hardening. Several PRs target the no-GIL build specifically. Tonghuaroot's PR 153063 fixes a crash iterating itertools tee concurrently — a genuine memory-safety issue, not just a documented race. PR 153057 fixes a data race compiling string.Template patterns. And PR 153061 from Victor…
Third, documentation cleanup: the http.cookiejar and http.server docs got a thorough pass fixing Sphinx reference warnings, led by Harjoth Khara and…
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