these 4 derivations will be built:
  /nix/store/rj31wxmdfwwffgvzsh9jxxb0v66nwfh1-crate-http-cache-reqwest-1.0.0-alpha.10.tar.gz.drv
  /nix/store/4ri2rlij1nslzj961d432i0iprrfv08p-http-cache-reqwest-1.0.0-alpha.10.drv
  /nix/store/yg6alcv7n9nz32h2mdp420xh0yy3nvfv-cargo-vendor-dir.drv
  /nix/store/jnwnv18cgkz1yhjy9b8rfy17pys773sc-citiesapp-frontend.drv