these 6 derivations will be built:
  /nix/store/0rgafsmn030p8xlc3gd8xrgf801mf7bc-cargo-package-proc-macro2-1.0.107.drv
  /nix/store/84xz3p1zmyi90glkfnfs8ma7lf4z93pl-source.drv
  /nix/store/cjsyhc6744axp8835bz9yqibk8wbfqsj-vendor-registry.drv
  /nix/store/ww5c75zbw7zrfyxcfzbmaifdmhk0yz6v-vendor-cargo-deps.drv
  /nix/store/g43vx29ynh3cvhah32rhsgyb45wp1lg3-harmonia-deps-3.1.0.drv
  /nix/store/a93p46jfrag03fwzqmdbi08rf7w8na7q-harmonia-llvm-cov-3.1.0.drv