'There is no error raised if the repository contains a tag which cannot
be parsed as a version.'

def test_unparseable_tags(self):

    self.repo.create_head('release/flocker-0.3.0unparseable')
    self.repo.create_tag('0.3.0unparseable')
    self.repo.create_head('release/flocker-0.3.0rc2')
    self.repo.create_tag('0.3.0rc2')
    self.assertEqual(self.calculate_base_branch(version='0.3.0rc3').name, 'master')
