this derivation will be built:
  /nix/store/a87xwvnrj6mnqxibwxlxv9mk0ii5pzgl-inputDerivation-effect-docs-pages.drv
building '/nix/store/a87xwvnrj6mnqxibwxlxv9mk0ii5pzgl-inputDerivation-effect-docs-pages.drv'...