these 2 derivations will be built:
  /nix/store/bfln2y5p1n9ybcdy6p5vm15phndxb08c-iets-0.1.0.drv
  /nix/store/bknngb7zq2bb8yx6c2nl05rh9zr2g0wa-iets-diff-e2e.drv