these 6 derivations will be built:
  /nix/store/kc83qni4sgxwswmqgw4k6wwy4vgaj02l-cargo-package-serde_json-1.0.154.drv
  /nix/store/m03crmkjyh83i813z7kndyzc9fn9mqqm-vendor-registry.drv
  /nix/store/3bkw6dnzdrqmim98aadcijdr0k6nwflv-vendor-cargo-deps.drv
  /nix/store/mqnk7x968a4w80dmn5qzak9rzjk5bgcf-source.drv
  /nix/store/7ysqicn98pwnshlvlbsvfj7mgkmghhk3-harmonia-deps-3.3.0.drv
  /nix/store/pyhx31kbjmax0502v2zpai4d1434madj-harmonia-llvm-cov-3.3.0.drv