these 2 derivations will be built:
  /nix/store/gc1hb3wcw51h3iyh2yj35f0cbs1xdxgb-mfeprimer-4.5.1-linux-amd64.gz.drv
  /nix/store/cfmyy0qhi7bw2i6122787cww0ay2x0b0-mfeprimer-4.5.1.drv