these 2 derivations will be built:
  /nix/store/8iy6g0irqsml58g6xhww980yy8myw4qh-harmonia-deps-3.3.0.drv
  /nix/store/59qfa7yjk2gi7qf9rqwljfb2rj4yvkb8-harmonia-llvm-cov-3.3.0.drv