these 4 derivations will be built:
  /nix/store/m8rj2hwvwn8sd4zyy4qj0ryx673jz9n3-Cargo.toml.drv
  /nix/store/3qz265z7nazygczmwkyfsp5c0fq1iqv2-source.drv
  /nix/store/xkfn2vs7ra5xdz5i3r8xsw0rvhbsi6mv-harmonia-deps-3.2.0.drv
  /nix/store/640y3p02hj1ygg9z01w0bpvmpv6djcm9-harmonia-3.2.0.drv