these 4 derivations will be built:
  /nix/store/118q15i23kl7zwh176jl8k99l965q4wx-source.drv
  /nix/store/bgbb8aw0l0k3zg0xh25azf44l5ykjd1n-but-0.21.2-vendor-staging.drv
  /nix/store/0mwjvycwyk1s3fmk1mvicv8jwzzr63sc-but-0.21.2-vendor.drv
  /nix/store/kvrik6f0ld7r5a8zq0m3lmw6zn32cra3-but-0.21.2.drv