these 2 derivations will be built:
  /nix/store/3cdv4q765xzxffxc1k4lc7g04w0xfww4-flake-inputs.drv
  /nix/store/pqbrl3b3x3j2s3ihxp0xbmxxbxvnpzsd-check-flake-inputs.drv