these 4 derivations will be built:
  /nix/store/fm7dx8jfi170rivi4afwn0gh02abjy0l-Cargo.toml.drv
  /nix/store/2a024ayi284189djxn9z7qb21m8v0d5z-source.drv
  /nix/store/1zva94app1nw2hg694f84p0d5nsv6zdq-harmonia-deps-3.3.0.drv
  /nix/store/vq3sk0jl5f46xv684an2lvkwaz42g6nc-harmonia-3.3.0.drv