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Emscripten: Remove obsolete pthread_getattr_np workaround in ceval.c #160873
Description
Bug report
Description
The workaround in Python/ceval.c was introduced to address a broken pthread_getattr_np() implementation in Emscripten versions prior to 4.0.6 (GH-130396, #131088).
The existing comment explicitly describes it as temporary:
#if defined(__EMSCRIPTEN__)
// Temporary workaround to make `pthread_getattr_np` work on Emscripten.
// Emscripten 4.0.6 will contain a fix:
// https://github.com/emscripten-core/emscripten/pull/23887However, the workaround is still enabled for all Emscripten versions because it only checks __EMSCRIPTEN__, regardless of the toolchain version.
The upstream fix was included in Emscripten 4.0.6, and CPython now uses Emscripten 6.0.13 (Platforms/emscripten/config.toml).
Therefore, this workaround appears to be obsolete and could potentially be removed, allowing CPython to use Emscripten's native pthread_getattr_np() implementation.
The removal should be verified against the current Emscripten toolchain to ensure that stack boundary detection and recursion protection continue to work correctly.
CPython versions tested on:
CPython main branch
Operating systems tested on:
Linux
Activity
pythongh-160873: Use -m64 and -pthread for Emscripten
lpyu001 commentedon Oct 29, 2026
Two more leftovers from older Emscripten versions:
Deprecated Emscripten flags in
configure.ac.--enable-wasm-pthreadslinks with-sUSE_PTHREADS, and thewasm64-*-emscriptentarget uses-sMEMORY64=1. Both settings were deprecated in Emscripten 6.0.1 in favor of-pthreadand-m64(Deprecate-sUSE_PTHREADSand-sMEMORY64in favor of standard flags. emscripten-core/emscripten#27025), and with 6.0.10 they emit-Wdeprecatedwarnings at link time. The replacements produce identical output. The default build doesn't use either option, so CI doesn't show the warnings.Obsolete Emscripten workaround in
test_pathlib.test_glob_dotdotusesNDOTDOTS = 48on Emscripten instead of 50, with a comment saying it can be removed once JS FS: Don't return ELOOP on a path with a large number of ..'s emscripten-core/emscripten#24591 is merged. That fix was merged in June 2025 (Emscripten 4.0.11+), so the workaround is no longer needed with the pinned 6.0.10.