src/__main__.py

"""
Configures the execution environment for the wheel_tool so that it can consume the dependencies we vendor and create
reproducible wheels
"""
import os

import src.extract_wheels as whl


def configure_reproducible_wheels():
    """
    Wheels created from sdists are not reproducible by default. We can however workaround this by
    patching in some configuration with environment variables.
    """

    # wheel, by default, enables debug symbols in GCC. This incidentally captures the build path in the .so file
    # We can override this behavior by disabling debug symbols entirely.
    # https://github.com/pypa/pip/issues/6505
    if os.environ.get("CFLAGS") is not None:
        os.environ["CFLAGS"] += " -g0"
    else:
        os.environ["CFLAGS"] = "-g0"

    # set SOURCE_DATE_EPOCH to 1980 so that we can use python wheels
    # https://github.com/NixOS/nixpkgs/blob/master/doc/languages-frameworks/python.section.md#python-setuppy-bdist_wheel-cannot-create-whl
    if os.environ.get("SOURCE_DATE_EPOCH") is None:
        os.environ["SOURCE_DATE_EPOCH"] = "315532800"

    # Python wheel metadata files can be unstable.
    # See https://bitbucket.org/pypa/wheel/pull-requests/74/make-the-output-of-metadata-files/diff
    if os.environ.get("PYTHONHASHSEED") is None:
        os.environ["PYTHONHASHSEED"] = "0"


if __name__ == "__main__":
    configure_reproducible_wheels()

    whl.main()