these 2 derivations will be built:
  /nix/store/8pzcb2wrgfx20sl0d1a5gsp4a8a8qf0p-cargo-vendor-dir.drv
  /nix/store/bs74nj4hb23dw6kdrdmb66hqw66sxph8-horae-tests-0.1.0.drv