cython>=0.28.1
cmake
# macOS py36 wheels are missing
# https://github.com/scikit-build/ninja-python-distributions/issues/12
# ninja

# latest scikit-build on PyPI does not support extra 'src' package_dir
-e git+https://github.com/scikit-build/scikit-build.git#egg=scikit-build

# we need wheel >= 0.31.0 to support Markdown long_description
wheel>=0.31.0
