anchor.diff:  
   stdenv.mkDerivation rec {
     pname = "devhelp";
  -  version = "40.1";
  +  version = "41.2";
  +
  +  outputs = [ "out" "devdoc" ];
   
     src = fetchurl {
       url = "mirror://gnome/sources/devhelp/${lib.versions.major version}/${pname}-${version}.tar.xz";
  -    sha256 = "PorZPoSEtEgjyuR0ov2dziLtbs0lZVWSzq17G2gya7s=";
  +    sha256 = "7KqQsPTaqPsgMPbcaQv1M/+Zp3NDf+Dhis/oLZl/YNI=";
     };
   
     nativeBuildInputs = [
  
positive.code: , gtk3
  , wrapGAppsHook
  , glib
  , amtk
  , appstream-glib
  , gobject-introspection
  , python3
  , webkitgtk
  , gettext
  , itstool
  
negative.code:     appstream-glib
      gobject-introspection
      python3
      gi-docgen
    ];
  
    buildInputs = [
      glib
      gtk3
      webkitgtk
      gnome.adwaita-icon-theme
      gsettings-desktop-schemas
    ];
  
    mesonFlags = [
      "-Dgtk_doc=true"
    ];
  
    doCheck = true;
  
    postPatch = ''
      # patchShebangs requires executable file
      chmod +x build-aux/meson/meson_post_install.py
      patchShebangs build-aux/meson/meson_post_install.py
    '';
  
    preFixup = ''
  