build.py

# Source: https://stackoverflow.com/a/63679316

import os

# See if Cython is installed
try:
    from Cython.Build import cythonize
    import numpy as np
# Do nothing if Cython is not available
except ImportError:
    # Got to provide this function. Otherwise, poetry will fail
    def build(setup_kwargs):
        pass


# Cython is installed. Compile
else:
    from setuptools import Extension
    from setuptools.dist import Distribution
    from distutils.command.build_ext import build_ext

    # This function will be executed in setup.py:
    def build(setup_kwargs):
        # The file you want to compile
        extensions = [
            Extension(
                "yolact.utils.cython_nms",
                ["yolact/utils/cython_nms.pyx"],
                include_dirs=[np.get_include()],
            )
        ]

        # gcc arguments hack: enable optimizations
        os.environ["CFLAGS"] = "-O3"

        # Build
        setup_kwargs.update(
            {
                "ext_modules": cythonize(
                    extensions,
                    language_level=3,
                    compiler_directives={"linetrace": True},
                ),
                "cmdclass": {"build_ext": build_ext},
            }
        )