Python 3.14a7: Segfault in sip_api_init_module / _Py_TYPE

[Florian Bruhin]

On 2025-04-13T09:21:41 , Phil Thompson wrote:
> 
> On 12/04/2025 21:13, Florian Bruhin wrote:
> > On 2025-04-11T20:57:32 , Phil Thompson wrote:
> >> 
> >> On 11/04/2025 16:15, Florian Bruhin wrote:
> >> > Hey,
> >> >
> >> > PyQt6 6.9.0 seemed to work fine with Python 3.14 Alpha 6 so far.
> >> > However, after upgrading to Alpha 7, "from PyQt6.QtCore" immediately
> >> > segfaults:
> >> >
> >> >     [...]
> >> >
> >> > I bisected this to this change in CPython, "Cache the result of
> >> > tuple_hash", which adds a new ob_hash field to PyTupleObject:
> >> >
> >> > https://github.com/python/cpython/pull/131529
> >> > https://github.com/python/cpython/commit/8614f86b7163b1c39798b481902dbb511292a537
> >> >
> >> > I'm not sure what happens there under the hood. Is there anything
> >> > special PyQt/sip is doing there, or is this simply some sort of CPython
> >> > regression in that commit? Happy to report it there, but I don't know
> >> > much about the CPython C API at all.
> >> >
> >> > Florian
> >> 
> >> Just by visual inspection of the code, I think the sequence of calls
> >> is...
> >> 
> >> [...]
> >> 
> >> ...so I don't think I'm doing anything bad.
> >> 
> >> Phil
> > 
> > Thanks, I opened a CPython issue here:
> > https://github.com/python/cpython/issues/132454
> > 
> > Florian
> 
> A quick check - I assume you are building PyQt6.sip from source against 
> the Alpha 7 headers.

I just tried rebuilding PyQt6-sip just to be sure:
https://bpa.st/SPHQ

Still seeing the same issue with that though.

I also tried rebuilding PyQt itself from sources, but that fails with:

    g++ -c -pipe -O2 -fno-exceptions -Wall -Wextra -mno-direct-extern-access -D_REENTRANT -fPIC -DSIP_PROTECTED_IS_PUBLIC -Dprotected=public -DQT_KEYPAD_NAVIGATION -DQT_NO_EXCEPTIONS -DQT_NO_DEBUG -DQT_PLUGIN -DQT_CORE_LIB -I. -I. -I.. -I/home/florian/tmp/pyqt-src/pyqt6-6.9.0/qpy/QtCore -I/usr/local/include/python3.14d -I/usr/include/qt6 -I/usr/include/qt6/QtCore -I. -I/usr/lib/qt6/mkspecs/linux-g++ -o sipQtCorecmodule.o sipQtCorecmodule.cpp
    In file included from sipAPIQtCore.h:29,
                     from sipQtCorecmodule.cpp:24:
    ../sip.h:14:10: fatal error: Python.h: No such file or directory

Can I somehow easily teach it to pass
-I/home/florian/proj/cpython/Include/ so I don't need to actually
install the Python dev build I'm testing against?

Florian

Florian
> 
> Phil
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