these 3 derivations will be built:
  /nix/store/2bvn8rfa4z7rbhjg3awiq28gn63q96dd-source.drv
  /nix/store/4pa5ybrsxm8qpk4azgsq1nwz4hp4jg0a-herdr-eternal-deps-0.1.0.drv
  /nix/store/k28fqvnq5fxh6r6mxb9jy6m93fv89rvz-herdr-eternal-test-0.1.0.drv