anchor.diff:    pname = "umockdev";
     version = "0.15.4";
   
  -  outputs = [ "bin" "out" "dev" "doc" ];
  +  outputs = [ "bin" "out" "dev" "devdoc" ];
   
     src = fetchurl {
       url = "https://github.com/martinpitt/umockdev/releases/download/${version}/${pname}-${version}.tar.xz";
  
positive.code:     })
    ];
  
    mesonFlags = [
      "-Dgtk_doc=true"
    ];
  
    buildInputs = [ glib systemd libgudev ];
  
    nativeBuildInputs = [
      docbook_xsl
      gobject-introspection
      gtk-doc
      meson
  
negative.code: { stdenv
  , lib
  , docbook-xsl-nons
  , fetchurl
  , fetchpatch
  , glib
  