def versions_from_vcs(tag_prefix, versionfile_source, verbose=False):
    # this runs 'git' from the root of the source tree. That either means
    # someone ran a setup.py command (and this code is in versioneer.py, so
    # IN_LONG_VERSION_PY=False, thus the containing directory is the root of
    # the source tree), or someone ran a project-specific entry point (and