ERROR:root:Error parsing
Traceback (most recent call last):
  File "/nix/store/bbn0bnyrryl4sxdkd7v14j2vnc7j7ssi-python2.7-pbr-3.1.1/lib/python2.7/site-packages/pbr/core.py", line 111, in pbr
    attrs = util.cfg_to_args(path, dist.script_args)
  File "/nix/store/bbn0bnyrryl4sxdkd7v14j2vnc7j7ssi-python2.7-pbr-3.1.1/lib/python2.7/site-packages/pbr/util.py", line 249, in cfg_to_args
    pbr.hooks.setup_hook(config)
  File "/nix/store/bbn0bnyrryl4sxdkd7v14j2vnc7j7ssi-python2.7-pbr-3.1.1/lib/python2.7/site-packages/pbr/hooks/__init__.py", line 25, in setup_hook
    metadata_config.run()
  File "/nix/store/bbn0bnyrryl4sxdkd7v14j2vnc7j7ssi-python2.7-pbr-3.1.1/lib/python2.7/site-packages/pbr/hooks/base.py", line 27, in run
    self.hook()
  File "/nix/store/bbn0bnyrryl4sxdkd7v14j2vnc7j7ssi-python2.7-pbr-3.1.1/lib/python2.7/site-packages/pbr/hooks/metadata.py", line 26, in hook
    self.config['name'], self.config.get('version', None))
  File "/nix/store/bbn0bnyrryl4sxdkd7v14j2vnc7j7ssi-python2.7-pbr-3.1.1/lib/python2.7/site-packages/pbr/packaging.py", line 755, in get_version
    name=package_name))
Exception: Versioning for this project requires either an sdist tarball, or access to an upstream git repository. It's also possible that there is a mismatch between the package name in setup.cfg and the argument given to pbr.version.VersionInfo. Project name testinfra was given, but was not able to be found.
error in setup command: Error parsing /tmp/nix-build-python2.7-testinfra-1.8.0.drv-0/testinfra-1.8.0/setup.cfg: Exception: Versioning for this project requires either an sdist tarball, or access to an upstream git repository. It's also possible that there is a mismatch between the package name in setup.cfg and the argument given to pbr.version.VersionInfo. Project name testinfra was given, but was not able to be found.
builder for ‘/nix/store/kl1phrhid0mvkhj06f3hdgs4x33gvm47-python2.7-testinfra-1.8.0.drv’ failed with exit code 1
cannot build derivation ‘/nix/store/qccsh388g2npb6jqlhgg4njp995mrcnq-python-2.7.13-env.drv’: 1 dependencies couldn't be built
cannot build derivation ‘/nix/store/rnvgyngzw6sdrfpqg3cw0jy2nk22m4sk-system-path.drv’: 1 dependencies couldn't be built
cannot build derivation ‘/nix/store/6wihh26gc8zai942sq52gwrd32pnfh81-nixos-system-T450s-18.03pre115134.d6f9c0b353.drv’: 1 dependencies couldn't be built
error: build of ‘/nix/store/6wihh26gc8zai942sq52gwrd32pnfh81-nixos-system-T450s-18.03pre115134.d6f9c0b353.drv’ failed