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:
        rendered = '0.post.dev%d' % pieces['distance']
    return rendered
