these 2 derivations will be built:
  /nix/store/71qmx43dqyrm2wvy4cc50ra1a8m2r652-harmonia-deps-3.3.0.drv
  /nix/store/flkpp5ql0pfv6p563qmr17n793yhv0n7-harmonia-llvm-cov-3.3.0.drv