these 4 derivations will be built:
  /nix/store/7il15ls992lvpx9i5c5kv9ybqnsglaq5-source.drv
  /nix/store/dixb9ssn7vsw3rjwa3cx4gkqd447gbnm-omp-17.2.15-cargo-vendor-vendor-staging.drv
  /nix/store/8ksq0wvn6k1hz7nyfvczvn7a7zdqakni-omp-17.2.15-cargo-vendor-vendor.drv
  /nix/store/3cmv0yjcy1wlkswvm7kkwja7lws850fy-omp-17.2.15.drv