def __init__(self, filename=None):
        self.filename = None
        if filename:
            self.load(filename)
def rename_source(self):
        """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.
        """
        # Note that this particular OpenFOAM requires absolute directories
        # to build correctly!
        parent   = os.path.dirname(self.stage.source_path)
        original = os.path.basename(self.stage.source_path)
        target   = 'OpenFOAM-{0}'.format(self.version)
        # Could also grep through etc/bashrc for WM_PROJECT_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))