Function updated_env

Platforms/emscripten/__main__.py:121–147

Create a new dict representing the environment to use. The changes made to the execution environment are printed out.

(updates, emsdk_cache)

def updated_env(updates, emsdk_cache):
    """Create a new dict representing the environment to use.

    The changes made to the execution environment are printed out.
    """
    env_defaults = {}
    # https://reproducible-builds.org/docs/source-date-epoch/
    git_epoch_cmd = ["git", "log", "-1", "--pretty=%ct"]
    try:
        epoch = subprocess.check_output(
            git_epoch_cmd, encoding="utf-8"
        ).strip()
        env_defaults["SOURCE_DATE_EPOCH"] = epoch
    except subprocess.CalledProcessError:
        pass  # Might be building from a tarball.
    # This layering lets SOURCE_DATE_EPOCH from os.environ takes precedence.
    environment = env_defaults | get_emsdk_environ(emsdk_cache) | updates
    env_diff = {}
    for key, value in environment.items():
        if os.environ.get(key) != value:
            env_diff[key] = value

    print("🌎 Environment changes:")
    for key in sorted(env_diff.keys()):
        print(f"  {key}={env_diff[key]}")

    return environment


def subdir(path_key, *, clean_ok=False):