def __download(self):
        """Set download source based on user parameters"""

        if not self.package and not self.repository and not self.url:
            self.url = 'https://developer.download.nvidia.com/compute/redist/nvshmem/{0}/source/nvshmem_src_{1}.txz'.format(self.__version.split('-')[0], self.__version)
Set download source based on user parameters
hpccm/building_blocks/nvshmem.py