If the passed service name is not available, but a unit file exist in
    /etc/systemd/system, return True. Otherwise, return False.

def _untracked_custom_unit_found(name, root=None):
    '''
    If the passed service name is not available, but a unit file exist in
    /etc/systemd/system, return True. Otherwise, return False.
    '''
    system = _root('/etc/systemd/system', root)
    unit_path = os.path.join(system, _canonical_unit_name(name))
    return os.access(unit_path, os.R_OK) and not _check_available(name)