these 5 derivations will be built:
  /nix/store/ybqmjn5gjm0jr6gajpangcn4yzk0a1l0-source.drv
  /nix/store/rfvy0jm40ifw615hx90b5sic5d4hwkf0-omp-18.12.0-cargo-vendor-vendor-staging.drv
  /nix/store/j6i0c7ach9bv0ddj6csh2h6x5xz0agah-omp-18.12.0-cargo-vendor-vendor.drv
  /nix/store/idg82p6qwawxw1h7ksv9sf9rzsj68hkk-omp-18.12.0.drv
  /nix/store/13i0j77rwj1nh37z3ii79jikfzxzxb8h-check-omp.drv