3.15.0a2 doesn't compile with CFLAGS=-DNDEBUG and --with-pydebug

Bug report

Bug description:

When configured using ./configure --with-pydebug (and explicitly not using --with-assertions), the build fails with:

+ make -j2 -C build-shared EXTRA_CFLAGS= LIBRARY=libpython3.15t-pic.a libpython3.15t-pic.a
make: Entering directory '/home/conda/feedstock_root/build_artifacts/python-split_1764324859162/work/build-shared'
x86_64-conda-linux-gnu-gcc -pthread -c -fno-strict-overflow -Wsign-compare -fno-omit-frame-pointer -mno-omit-leaf-frame-pointer -g -Og -Wall -march=nocona -mtune=haswell -ftree-vectorize -fPIC -fstack-protector-strong -fno-plt -O0 -ffunction-sections -pipe -isystem /home/conda/feedstock_root/build_artifacts/python-split_1764324859162/_h_env_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehol/include -fdebug-prefix-map=/home/conda/feedstock_root/build_artifacts/python-split_1764324859162/work=/usr/local/src/conda/python-3.15.0a2 -fdebug-prefix-map=/home/conda/feedstock_root/build_artifacts/python-split_1764324859162/_h_env_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehol=/usr/local/src/conda-prefix -march=nocona -mtune=haswell -ftree-vectorize -fPIC -fstack-protector-strong -fno-plt -O0 -ffunction-sections -pipe -isystem /home/conda/feedstock_root/build_artifacts/python-split_1764324859162/_h_env_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehol/include -fdebug-prefix-map=/home/conda/feedstock_root/build_artifacts/python-split_1764324859162/work=/usr/local/src/conda/python-3.15.0a2 -fdebug-prefix-map=/home/conda/feedstock_root/build_artifacts/python-split_1764324859162/_h_env_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehol=/usr/local/src/conda-prefix  -std=c11 -Wextra -Wno-unused-parameter -Wno-missing-field-initializers -Wstrict-prototypes -Werror=implicit-function-declaration -fvisibility=hidden  -I/home/conda/feedstock_root/build_artifacts/python-split_1764324859162/work/Include/internal -I/home/conda/feedstock_root/build_artifacts/python-split_1764324859162/work/Include/internal/mimalloc -IObjects -IInclude -IPython -I. -I/home/conda/feedstock_root/build_artifacts/python-split_1764324859162/work/Include -DNDEBUG -D_FORTIFY_SOURCE=2 -O0 -isystem /home/conda/feedstock_root/build_artifacts/python-split_1764324859162/_h_env_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehol/include -I/home/conda/feedstock_root/build_artifacts/python-split_1764324859162/_h_env_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehol/include -DNDEBUG -D_FORTIFY_SOURCE=2 -O0 -isystem /home/conda/feedstock_root/build_artifacts/python-split_1764324859162/_h_env_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehol/include -I/home/conda/feedstock_root/build_artifacts/python-split_1764324859162/_h_env_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehol/include -fPIC -DPy_BUILD_CORE -o Objects/typeobject.o /home/conda/feedstock_root/build_artifacts/python-split_1764324859162/work/Objects/typeobject.c
x86_64-conda-linux-gnu-gcc -pthread -c -fno-strict-overflow -Wsign-compare -fno-omit-frame-pointer -mno-omit-leaf-frame-pointer -g -Og -Wall -march=nocona -mtune=haswell -ftree-vectorize -fPIC -fstack-protector-strong -fno-plt -O0 -ffunction-sections -pipe -isystem /home/conda/feedstock_root/build_artifacts/python-split_1764324859162/_h_env_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehol/include -fdebug-prefix-map=/home/conda/feedstock_root/build_artifacts/python-split_1764324859162/work=/usr/local/src/conda/python-3.15.0a2 -fdebug-prefix-map=/home/conda/feedstock_root/build_artifacts/python-split_1764324859162/_h_env_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehol=/usr/local/src/conda-prefix -march=nocona -mtune=haswell -ftree-vectorize -fPIC -fstack-protector-strong -fno-plt -O0 -ffunction-sections -pipe -isystem /home/conda/feedstock_root/build_artifacts/python-split_1764324859162/_h_env_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehol/include -fdebug-prefix-map=/home/conda/feedstock_root/build_artifacts/python-split_1764324859162/work=/usr/local/src/conda/python-3.15.0a2 -fdebug-prefix-map=/home/conda/feedstock_root/build_artifacts/python-split_1764324859162/_h_env_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehol=/usr/local/src/conda-prefix  -std=c11 -Wextra -Wno-unused-parameter -Wno-missing-field-initializers -Wstrict-prototypes -Werror=implicit-function-declaration -fvisibility=hidden  -I/home/conda/feedstock_root/build_artifacts/python-split_1764324859162/work/Include/internal -I/home/conda/feedstock_root/build_artifacts/python-split_1764324859162/work/Include/internal/mimalloc -IObjects -IInclude -IPython -I. -I/home/conda/feedstock_root/build_artifacts/python-split_1764324859162/work/Include -DNDEBUG -D_FORTIFY_SOURCE=2 -O0 -isystem /home/conda/feedstock_root/build_artifacts/python-split_1764324859162/_h_env_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehol/include -I/home/conda/feedstock_root/build_artifacts/python-split_1764324859162/_h_env_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehol/include -DNDEBUG -D_FORTIFY_SOURCE=2 -O0 -isystem /home/conda/feedstock_root/build_artifacts/python-split_1764324859162/_h_env_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehol/include -I/home/conda/feedstock_root/build_artifacts/python-split_1764324859162/_h_env_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehol/include -fPIC -DPy_BUILD_CORE -o Objects/unicode_format.o /home/conda/feedstock_root/build_artifacts/python-split_1764324859162/work/Objects/unicode_format.c
In file included from /home/conda/feedstock_root/build_artifacts/python-split_1764324859162/_build_env/x86_64-conda-linux-gnu/sysroot/usr/include/assert.h:36,
                 from /home/conda/feedstock_root/build_artifacts/python-split_1764324859162/work/Include/Python.h:20,
                 from /home/conda/feedstock_root/build_artifacts/python-split_1764324859162/work/Objects/unicode_format.c:43:
/home/conda/feedstock_root/build_artifacts/python-split_1764324859162/_build_env/x86_64-conda-linux-gnu/sysroot/usr/include/features.h:330:4: warning: #warning _FORTIFY_SOURCE requires compiling with optimization (-O) [-Wcpp]
  330 | #  warning _FORTIFY_SOURCE requires compiling with optimization (-O)
      |    ^~~~~~~
In file included from /home/conda/feedstock_root/build_artifacts/python-split_1764324859162/_build_env/x86_64-conda-linux-gnu/sysroot/usr/include/assert.h:36,
                 from /home/conda/feedstock_root/build_artifacts/python-split_1764324859162/work/Include/Python.h:20,
                 from /home/conda/feedstock_root/build_artifacts/python-split_1764324859162/work/Objects/typeobject.c:3:
/home/conda/feedstock_root/build_artifacts/python-split_1764324859162/_build_env/x86_64-conda-linux-gnu/sysroot/usr/include/features.h:330:4: warning: #warning _FORTIFY_SOURCE requires compiling with optimization (-O) [-Wcpp]
  330 | #  warning _FORTIFY_SOURCE requires compiling with optimization (-O)
      |    ^~~~~~~
In file included from /home/conda/feedstock_root/build_artifacts/python-split_1764324859162/work/Include/internal/pycore_weakref.h:11,
                 from /home/conda/feedstock_root/build_artifacts/python-split_1764324859162/work/Objects/typeobject.c:24:
/home/conda/feedstock_root/build_artifacts/python-split_1764324859162/work/Include/internal/pycore_critical_section.h: In function '_PyCriticalSection_AssertHeld':
/home/conda/feedstock_root/build_artifacts/python-split_1764324859162/work/Include/internal/pycore_critical_section.h:221:29: warning: unused variable 'cs' [-Wunused-variable]
  221 |         PyCriticalSection2 *cs = (PyCriticalSection2 *)(prev & ~_Py_CRITICAL_SECTION_MASK);
      |                             ^~
/home/conda/feedstock_root/build_artifacts/python-split_1764324859162/work/Include/internal/pycore_critical_section.h:225:28: warning: unused variable 'cs' [-Wunused-variable]
  225 |         PyCriticalSection *cs = (PyCriticalSection *)(tstate->critical_section & ~_Py_CRITICAL_SECTION_MASK);
      |                            ^~
/home/conda/feedstock_root/build_artifacts/python-split_1764324859162/work/Include/internal/pycore_critical_section.h: In function '_PyCriticalSection_AssertHeldObj':
/home/conda/feedstock_root/build_artifacts/python-split_1764324859162/work/Include/internal/pycore_critical_section.h:240:29: warning: unused variable 'cs' [-Wunused-variable]
  240 |         PyCriticalSection2 *cs = (PyCriticalSection2 *)(prev & ~_Py_CRITICAL_SECTION_MASK);
      |                             ^~
/home/conda/feedstock_root/build_artifacts/python-split_1764324859162/work/Include/internal/pycore_critical_section.h:246:28: warning: unused variable 'cs' [-Wunused-variable]
  246 |         PyCriticalSection *cs = (PyCriticalSection *)(prev & ~_Py_CRITICAL_SECTION_MASK);
      |                            ^~
/home/conda/feedstock_root/build_artifacts/python-split_1764324859162/work/Include/internal/pycore_critical_section.h:236:14: warning: unused variable 'mutex' [-Wunused-variable]
  236 |     PyMutex *mutex = &_PyObject_CAST(op)->ob_mutex;
      |              ^~~~~
/home/conda/feedstock_root/build_artifacts/python-split_1764324859162/work/Objects/typeobject.c: In function 'set_tp_bases':
/home/conda/feedstock_root/build_artifacts/python-split_1764324859162/work/Objects/typeobject.c:106:10: error: implicit declaration of function 'types_world_is_stopped' [-Wimplicit-function-declaration]
  106 |     if (!types_world_is_stopped()) { _Py_CRITICAL_SECTION_ASSERT_MUTEX_LOCKED(TYPE_LOCK); }
      |          ^~~~~~~~~~~~~~~~~~~~~~
/home/conda/feedstock_root/build_artifacts/python-split_1764324859162/work/Objects/typeobject.c:113:33: note: in expansion of macro 'ASSERT_TYPE_LOCK_HELD'
  113 |     if (TYPE_IS_REVEALED(tp)) { ASSERT_TYPE_LOCK_HELD(); }
      |                                 ^~~~~~~~~~~~~~~~~~~~~
/home/conda/feedstock_root/build_artifacts/python-split_1764324859162/work/Objects/typeobject.c:604:5: note: in expansion of macro 'ASSERT_NEW_TYPE_OR_LOCKED'
  604 |     ASSERT_NEW_TYPE_OR_LOCKED(self);
      |     ^~~~~~~~~~~~~~~~~~~~~~~~~

This was introduced in #140133 which tried to fix #133177

CPython versions tested on:

3.15

Operating systems tested on:

Linux

Linked PRs

gh-142038: Expand guard for types_world_is_stopped to fix debug builds without assertions #142039

pythongh-142038: Expand guard for types_world_is_stopped to fix debug…

I cannot reproduce this issue.

When configured using ./configure --with-pydebug

Are you sure that you used exactly ./configure --with-pydebug?

No, I'm using more than this. This popped up while setting up the build for conda-forge conda-forge/python-feedstock#833 I'll try to produce a minimal example.

Can you provide the whole configure command and/or logs including the command?

This fails (see conda-forge/python-feedstock#835 and conda-forge/python-feedstock#837 ):

./configure --prefix=$PREFIX --build=x86_64-conda-linux-gnu --host=x86_64-conda-linux-gnu --enable-ipv6 --with-ensurepip=no --with-tzpath=$PREFIX/share/zoneinfo --with-computed-gotos --with-system-expat --enable-loadable-sqlite-extensions --with-tcltk-includes=-I$PREFIX/include '--with-tcltk-libs=-L$PREFIX/lib -ltcl8.6 -ltk8.6' --with-platlibdir=lib --enable-experimental-jit=no --disable-gil --with-pydebug --oldincludedir=$BUILD_PREFIX/x86_64-conda-linux-gnu/sysroot/usr/include --enable-shared

Full log: 19.txt

But removing --disable-gil makes the build pass (which makes sense as the whole block is guarded with #ifdef Py_GIL_DISABLED)

./configure --prefix=$PREFIX--disable-gil --with-pydebug was also sufficient to trigger this, but I realised that we were setting -DNDEBUG externally. Thus:

I guess my fix is not the right one here. Should we instead add a test to configure to check that NDEBUG is not part of the CFLAGS if a debug build has been requested?

Oh ok, I can reproduce the build failure with:

./configure --with-pydebug --disable-gil CFLAGS="-DNDEBUG"

Well, it's uncommon to disable assertions in a debug build. But we should support it.

gh-142038: Expand guard for types_world_is_stopped() to fix debug bui…

I merged your fix. Thanks.

pythongh-142038: Expand guard for types_world_is_stopped() to fix deb…

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3.15.0a2 doesn't compile with `CFLAGS=-DNDEBUG` and `--with-pydebug` #142038

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3.15.0a2 doesn't compile with CFLAGS=-DNDEBUG and --with-pydebug #142038

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vstinner commented on Dec 2, 2025

xhochy commented on Dec 2, 2025

vstinner commented on Dec 2, 2025

xhochy commented on Dec 3, 2025

vstinner commented on Dec 3, 2025

vstinner commented on Dec 3, 2025

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3.15.0a2 doesn't compile with `CFLAGS=-DNDEBUG` and `--with-pydebug` #142038