BUG: doc build on 3.14t interpreter leads to bus error #30681
Description
When I run PYTHONFAULTHANDLER=1 spin docs with a free-threaded interpreter on my ARM Macbook Pro, the doc build crashes with a bus error and the following faulthandler output:
Details
Running Sphinx v7.2.6
Fatal Python error: Segmentation fault
<Cannot show all threads while the GIL is disabled>
Stack (most recent call first):
File "/Users/goldbaum/Documents/numpy/doc/source/conf.py", line 58 in replace_scalar_type_names
File "/Users/goldbaum/Documents/numpy/doc/source/conf.py", line 65 in <module>
File "/Users/goldbaum/.pyenv/versions/3.14.2t/lib/python3.14t/site-packages/sphinx/config.py", line 358 in eval_config_file
File "/Users/goldbaum/.pyenv/versions/3.14.2t/lib/python3.14t/site-packages/sphinx/config.py", line 181 in read
File "/Users/goldbaum/.pyenv/versions/3.14.2t/lib/python3.14t/site-packages/sphinx/application.py", line 211 in __init__
File "/Users/goldbaum/.pyenv/versions/3.14.2t/lib/python3.14t/site-packages/sphinx/cmd/build.py", line 293 in build_main
File "/Users/goldbaum/.pyenv/versions/3.14.2t/lib/python3.14t/site-packages/sphinx/cmd/build.py", line 341 in main
File "/Users/goldbaum/.pyenv/versions/3.14.2t/bin/sphinx-build", line 7 in <module>
Current thread's C stack trace (most recent call first):
Binary file "/Users/goldbaum/.pyenv/versions/3.14.2t/lib/libpython3.14t.dylib", at _Py_DumpStack+0x44 [0x105744a64]
Binary file "/Users/goldbaum/.pyenv/versions/3.14.2t/lib/libpython3.14t.dylib", at faulthandler_fatal_error+0x240 [0x1057588d4]
Binary file "/usr/lib/system/libsystem_platform.dylib", at _sigtramp+0x38 [0x189d4d6a4]
Binary file "/Users/goldbaum/.pyenv/versions/3.14.2t/lib/libpython3.14t.dylib", at setitem_take2_lock_held+0x3c [0x1055a1c2c]
Binary file "/Users/goldbaum/.pyenv/versions/3.14.2t/lib/libpython3.14t.dylib", at PyDict_SetItem+0x100 [0x1055a1ebc]
Binary file "/Users/goldbaum/.pyenv/versions/3.14.2t/lib/libpython3.14t.dylib", at _PyEval_EvalFrameDefault+0xf728 [0x1056ad6b0]
Binary file "/Users/goldbaum/.pyenv/versions/3.14.2t/lib/libpython3.14t.dylib", at PyEval_EvalCode+0x25c [0x10569da00]
Binary file "/Users/goldbaum/.pyenv/versions/3.14.2t/lib/libpython3.14t.dylib", at builtin_exec+0x608 [0x105699278]
Binary file "/Users/goldbaum/.pyenv/versions/3.14.2t/lib/libpython3.14t.dylib", at PyObject_Vectorcall+0x58 [0x10554df98]
Binary file "/Users/goldbaum/.pyenv/versions/3.14.2t/lib/libpython3.14t.dylib", at _PyEval_EvalFrameDefault+0x2364 [0x1056a02ec]
Binary file "/Users/goldbaum/.pyenv/versions/3.14.2t/lib/libpython3.14t.dylib", at _PyEval_Vector+0x2cc [0x10569dce0]
Binary file "/Users/goldbaum/.pyenv/versions/3.14.2t/lib/libpython3.14t.dylib", at _PyObject_VectorcallDictTstate+0xcc [0x10554d658]
Binary file "/Users/goldbaum/.pyenv/versions/3.14.2t/lib/libpython3.14t.dylib", at _PyObject_Call_Prepend+0x98 [0x10554e88c]
Binary file "/Users/goldbaum/.pyenv/versions/3.14.2t/lib/libpython3.14t.dylib", at call_method+0x7c [0x105600284]
Binary file "/Users/goldbaum/.pyenv/versions/3.14.2t/lib/libpython3.14t.dylib", at slot_tp_init+0x2c [0x105608678]
Binary file "/Users/goldbaum/.pyenv/versions/3.14.2t/lib/libpython3.14t.dylib", at type_call+0x1c0 [0x1055f806c]
Binary file "/Users/goldbaum/.pyenv/versions/3.14.2t/lib/libpython3.14t.dylib", at _PyObject_MakeTpCall+0x148 [0x10554d804]
Binary file "/Users/goldbaum/.pyenv/versions/3.14.2t/lib/libpython3.14t.dylib", at _PyEval_EvalFrameDefault+0x2364 [0x1056a02ec]
Binary file "/Users/goldbaum/.pyenv/versions/3.14.2t/lib/libpython3.14t.dylib", at PyEval_EvalCode+0x25c [0x10569da00]
Binary file "/Users/goldbaum/.pyenv/versions/3.14.2t/lib/libpython3.14t.dylib", at run_mod+0x270 [0x105729ef0]
Binary file "/Users/goldbaum/.pyenv/versions/3.14.2t/lib/libpython3.14t.dylib", at _PyRun_SimpleFileObject+0x390 [0x1057269a4]
Binary file "/Users/goldbaum/.pyenv/versions/3.14.2t/lib/libpython3.14t.dylib", at _PyRun_AnyFileObject+0xa0 [0x10572626c]
Binary file "/Users/goldbaum/.pyenv/versions/3.14.2t/lib/libpython3.14t.dylib", at pymain_run_file+0x14c [0x105754d5c]
Binary file "/Users/goldbaum/.pyenv/versions/3.14.2t/lib/libpython3.14t.dylib", at Py_RunMain+0x778 [0x105754428]
Binary file "/Users/goldbaum/.pyenv/versions/3.14.2t/lib/libpython3.14t.dylib", at pymain_main+0x144 [0x10575477c]
Binary file "/Users/goldbaum/.pyenv/versions/3.14.2t/lib/libpython3.14t.dylib", at Py_BytesMain+0x28 [0x10575481c]
Binary file "/usr/lib/dyld", at start+0x17bc [0x189972b98]
Extension modules: PIL._imaging, markupsafe._speedups, numpy._core._multiarray_umath, numpy.linalg._umath_linalg (total: 4)
make: *** [html-build] Segmentation fault: 11
The most relevant line in the Python traceback is:
File "/Users/goldbaum/Documents/numpy/doc/source/conf.py", line 58 in replace_scalar_type_names
Which corresponds to this line:
Line 58 in fba740c
I'm pretty sure that writing to tp_name like this via ctypes is undefined behavior. For static types tp_name is embedded in the binary. I'm a little surprised it works at all in the GIL-enabled build.
Ping @mattip since you last touched this code.