TAG[.post.devDISTANCE] -- No -dirty.

    Exceptions:
    1: no tags. 0.post.devDISTANCE

def render_pep440_pre(pieces):
    """TAG[.post.devDISTANCE] -- No -dirty.

    Exceptions:
    1: no tags. 0.post.devDISTANCE
    """
    if pieces["closest-tag"]:
        rendered = pieces["closest-tag"]
        if pieces["distance"]:
            rendered += ".post.dev%d" % pieces["distance"]
    else:
        # exception #1
        rendered = "0.post.dev%d" % pieces["distance"]
    return rendered