'This is fairly horrible.
The github tarfiles have weird names that do not correspond to the
canonical name. We need to rename these, but leave a symlink for
spack to work with.'

def rename_source(self):

    parent = os.path.dirname(self.stage.source_path)
    original = os.path.basename(self.stage.source_path)
    target = 'OpenFOAM-{0}'.format(self.version)
    with working_dir(parent):
        if ((original != target) and (not os.path.lexists(target))):
            os.rename(original, target)
            os.symlink(target, original)
            tty.info('renamed    {0}    ->    {1}'.format(original, target))
