these 3 derivations will be built:
  /nix/store/pkmqrpll647nrz03p1lmxrsipcc19h56-devshell-env.bash.drv
  /nix/store/bqjziqvbxf8cplhfr293hq0kim7nfplw-devshell-dir.drv
  /nix/store/h79a1pqg0gimzs8k9i4vcg266v6y0929-devshell.drv