def clean_semver(cls, version_spec):
        return re.sub(r"([<>=~])\s+?v?", "\\1", version_spec, re.IGNORECASE)
def mkhead(repo: 'Repo', path: PathLike) -> 'Head':
    """:return: New branch/head instance"""
    return git.Head(repo, git.Head.to_full_path(path))