Bug#1116453: mpi4py: FTBFS on sh4: too large for field of 2 bytes

Source: mpi4py
Version: 4.1.0-8
Severity: serious
Tags: ftbfs
Justification: FTBFS
X-Debbugs-Cc: [email protected]
User: [email protected]
Usertags: sh4

mpi4py has started failing to build on sh4:

building 'mpi4py.MPI' extension
creating build/temp.linux-sh4-cpython-313/src/mpi4py
/usr/bin/mpicc -g -O2 -Werror=implicit-function-declaration -ffile-prefix-map=/<<PKGBUILDDIR>>=. -fstack-protector-strong -Wformat -Werror=format-security -D_LARGEFILE_SOURCE -D_FILE_OFFSET_BITS=64 -D_TIME_BITS=64 -Wdate-time -D_FORTIFY_SOURCE=2 -fPIC -DPYMPIABI=1 -DHAVE_DLFCN_H=1 -DHAVE_DLOPEN=1 -Isrc -I/usr/include/python3.13 -c src/mpi4py/MPI.c -o build/temp.linux-sh4-cpython-313/src/mpi4py/MPI.o
src/mpi4py/MPI.c: In function ‘__pyx_pymod_exec_MPI’:
src/mpi4py/MPI.c:289780:30: note: variable tracking size limit exceeded with ‘-fvar-tracking-assignments’, retrying without
289780 | static CYTHON_SMALL_CODE int __pyx_pymod_exec_MPI(PyObject *__pyx_pyinit_module)
       |                              ^~~~~~~~~~~~~~~~~~~~
/tmp/cczUpbyN.s: Assembler messages:
/tmp/cczUpbyN.s:8852502: Error: value of 0001528e too large for field of 2 bytes at 0003995f
error: command '/usr/bin/mpicc' failed with exit code 1


Likely due to changes in gcc-15, aided and abetted by cython 3.0.
Upstream suggests building with -DCYTHON_LIMITED_API=1
see https://github.com/mpi4py/mpi4py/pull/690#issuecomment-3337456651


-- System Information:
Debian Release: forky/sid
  APT prefers unstable-debug
  APT policy: (500, 'unstable-debug'), (500, 'unstable'), (1, 'experimental')
Architecture: amd64 (x86_64)
Foreign Architectures: i386

Kernel: Linux 6.16.7+deb14-amd64 (SMP w/8 CPU threads; PREEMPT)
Kernel taint flags: TAINT_PROPRIETARY_MODULE, TAINT_WARN, TAINT_OOT_MODULE
Locale: LANG=en_AU.UTF-8, LC_CTYPE=en_AU.UTF-8 (charmap=UTF-8), LANGUAGE=en_AU:en
Shell: /bin/sh linked to /usr/bin/dash
Init: systemd (via /run/systemd/system)
LSM: AppArmor: enabled