these 2 derivations will be built:
  /nix/store/79w0g8g2gl8b83lr6d8jxm4hwmajzg0k-harmonia-deps-3.2.0.drv
  /nix/store/kdgxi5vqanidgyhay9515czh7jxgqgm3-harmonia-llvm-cov-3.2.0.drv