[build-system]
build-backend = "setuptools.build_meta:__legacy__"
requires = [
     "setuptools >= 40.8.0",
     "wheel",

     # Python 3.7 requires at least Cython 0.27.3.
     # 0.28 is faster, and (important!) lets us specify the target module
     # name to be created so that we can have both foo.py and _foo.so
     # at the same time. 0.29 fixes some issues with Python 3.7,
     # and adds the 3str mode for transition to Python 3.
     "Cython >= 0.29.6",
     # See version requirements in setup.py
     "cffi >= 1.12.2 ; platform_python_implementation == 'CPython'",
     # Python 3.7 requires at least 0.4.14, which is ABI incompatible with earlier
     "greenlet>=0.4.14 ; platform_python_implementation == 'CPython'",
]