these 2 derivations will be built:
  /nix/store/fbhci789176dz8nrryxd763260jlw041-mfeprimer-4.5.1-linux-amd64.gz.drv
  /nix/store/n4nqf0bgzzvkibmxdppgxpbwgx7ax948-mfeprimer-4.5.1.drv