anchor.diff:    nativeBuildInputs = [
       python3
       re2c
  +    installShellFiles
     ]
     ++ lib.optionals buildDocs [
       asciidoc
  
positive.code: , asciidoc
  , docbook_xml_dtd_45
  , docbook_xsl
  , libxslt
  , python3
  , re2c
  
negative.code:     runHook preInstall
  
      install -Dm555 -t $out/bin ninja
      installShellCompletion --name ninja \
        --bash misc/bash-completion \
        --zsh misc/zsh-completion
    '' + lib.optionalString buildDocs ''
      install -Dm444 -t $out/share/doc/ninja doc/manual.asciidoc doc/manual.html
    '' + ''
  