Unable to install on macos 15.5

[emir-radkevich]

Hi.

Trying to install gcc@8:

(pytometry) emir.radkevich@MLSKFV4DLQXLL ~ % brew install gcc@8
Warning: No available formula with the name "gcc@8". Did you mean gcc or gcc@9?
==> Searching for similarly named formulae and casks...
==> Formulae
gcc                                      gcc@9

To install gcc, run:
  brew install gcc

Simply ran brew install gcc, set up export CC=/opt/homebrew/Cellar/gcc/15.1.0/bin/gcc-15, and still cannot install:

pip install mnnpy

Building wheels for collected packages: mnnpy DEPRECATION: Building 'mnnpy' using the legacy setup.py bdist_wheel mechanism, which will be removed in a future version. pip 25.3 will enforce this behaviour change. A possible replacement is to use the standardized build interface by setting the `--use-pep517` option, (possibly combined with `--no-build-isolation`), or adding a `pyproject.toml` file to the source tree of 'mnnpy'. Discussion can be found at https://github.com/pypa/pip/issues/6334 Building wheel for mnnpy (setup.py) ... error error: subprocess-exited-with-error

× python setup.py bdist_wheel did not run successfully.
│ exit code: 1
╰─> [69 lines of output]
Building with c.
/Users/emir.radkevich/anaconda3/envs/pytometry/lib/python3.12/site-packages/setuptools/dist.py:599: SetuptoolsDeprecationWarning: Invalid dash-separated key 'python-tag' in 'bdist_wheel' (setup.cfg), please use the underscore name 'python_tag' instead.
!!

          ********************************************************************************
          Usage of dash-separated 'python-tag' will not be supported in future
          versions. Please use the underscore name 'python_tag' instead.

          By 2026-Mar-03, you need to update your project and remove deprecated calls
          or your builds will no longer be supported.

          See https://setuptools.pypa.io/en/latest/userguide/declarative_config.html for details.
          ********************************************************************************
  !!
    opt = self._enforce_underscore(opt, section)
  /Users/emir.radkevich/anaconda3/envs/pytometry/lib/python3.12/site-packages/setuptools/dist.py:599: SetuptoolsDeprecationWarning: Invalid dash-separated key 'python-tag' in 'bdist_wheel' (setup.cfg), please use the underscore name 'python_tag' instead.
  !!

          ********************************************************************************
          Usage of dash-separated 'python-tag' will not be supported in future
          versions. Please use the underscore name 'python_tag' instead.
          (Affected: mnnpy).

          By 2026-Mar-03, you need to update your project and remove deprecated calls
          or your builds will no longer be supported.

          See https://setuptools.pypa.io/en/latest/userguide/declarative_config.html for details.
          ********************************************************************************

  !!
    opt = self._enforce_underscore(opt, section)
  /Users/emir.radkevich/anaconda3/envs/pytometry/lib/python3.12/site-packages/setuptools/dist.py:759: SetuptoolsDeprecationWarning: License classifiers are deprecated.
  !!

          ********************************************************************************
          Please consider removing the following classifiers in favor of a SPDX license expression:

          License :: OSI Approved :: BSD License

          See https://packaging.python.org/en/latest/guides/writing-pyproject-toml/#license for details.
          ********************************************************************************

  !!
    self._finalize_license_expression()
  running bdist_wheel
  running build
  running build_py
  file irlb.py (for module irlb) not found
  file mnn.py (for module mnn) not found
  file utils.py (for module utils) not found
  creating build/lib.macosx-11.1-arm64-cpython-312/mnnpy
  copying mnnpy/irlb.py -> build/lib.macosx-11.1-arm64-cpython-312/mnnpy
  copying mnnpy/__init__.py -> build/lib.macosx-11.1-arm64-cpython-312/mnnpy
  copying mnnpy/utils.py -> build/lib.macosx-11.1-arm64-cpython-312/mnnpy
  copying mnnpy/mnn.py -> build/lib.macosx-11.1-arm64-cpython-312/mnnpy
  copying mnnpy/settings.py -> build/lib.macosx-11.1-arm64-cpython-312/mnnpy
  file irlb.py (for module irlb) not found
  file mnn.py (for module mnn) not found
  file utils.py (for module utils) not found
  running build_ext
  building 'mnnpy._utils' extension
  creating build/temp.macosx-11.1-arm64-cpython-312/mnnpy
  /opt/homebrew/Cellar/gcc/15.1.0/bin/gcc-15 -fno-strict-overflow -Wsign-compare -Wunreachable-code -DNDEBUG -O2 -Wall -fPIC -O2 -isystem /Users/emir.radkevich/anaconda3/envs/pytometry/include -arch arm64 -fPIC -O2 -isystem /Users/emir.radkevich/anaconda3/envs/pytometry/include -arch arm64 -I/Users/emir.radkevich/anaconda3/envs/pytometry/include/python3.12 -c mnnpy/_utils.c -o build/temp.macosx-11.1-arm64-cpython-312/mnnpy/_utils.o -O2 -ffast-math -march=native -fopenmp
  mnnpy/_utils.c:208:12: fatal error: longintrepr.h: No such file or directory
    208 |   #include "longintrepr.h"
        |            ^~~~~~~~~~~~~~~
  compilation terminated.
  error: command '/opt/homebrew/Cellar/gcc/15.1.0/bin/gcc-15' failed with exit code 1
  [end of output]

note: This error originates from a subprocess, and is likely not a problem with pip.
ERROR: Failed building wheel for mnnpy
Running setup.py clean for mnnpy
Failed to build mnnpy
ERROR: Failed to build installable wheels for some pyproject.toml based projects (mnnpy)

Thank you,
Emir.