def _arch(self, pkg):
    arch = self._specs[pkg].architecture
    if (not arch):
        arch = spack.spec.ArchSpec()
        self._specs[pkg].architecture = arch
    return arch
def _arch(self, pkg):
    arch = self._specs[pkg].architecture
    if (not arch):
        arch = spack.spec.ArchSpec()
        self._specs[pkg].architecture = arch
    return arch