def __distro(self):
        """Based on the Linux distribution, set values accordingly.  A user
        specified value overrides any defaults."""

        if hpccm.config.g_linux_distro == linux_distro.UBUNTU:
            self.__runtime_ospackages = ['libatomic1']
        elif hpccm.config.g_linux_distro == linux_distro.CENTOS:
            pass
        else: # pragma: no cover
            raise RuntimeError('Unknown Linux distribution')
Based on the Linux distribution, set values accordingly.  A user
        specified value overrides any defaults.
hpccm/building_blocks/pnetcdf.py