this derivation will be built:
  /nix/store/k9c7as6m4m49lh2gh5b6acanlnwn9zcq-inputDerivation-effect-docs-pages.drv
building '/nix/store/k9c7as6m4m49lh2gh5b6acanlnwn9zcq-inputDerivation-effect-docs-pages.drv'...