anchor.diff:  
     meta = with stdenv.lib; {
       description = "API documentation browser for GNOME";
  -    homepage = https://wiki.gnome.org/Apps/Devhelp;
  -    license = licenses.gpl2;
  +    homepage = "https://wiki.gnome.org/Apps/Devhelp";
  +    license = licenses.gpl3Plus;
       maintainers = gnome3.maintainers;
       platforms = platforms.linux;
     };
  
positive.code:     sha256 = "0zpmn6fgkgiayvn4diia5df0s6s7dqrdnp3nrvpavsmgn0vhb4pg";
    };
  
    nativeBuildInputs = [ meson ninja pkgconfig gettext itstool wrapGAppsHook appstream-glib gobject-introspection python3 ];
    buildInputs = [
      glib gtk3 webkitgtk amtk
      gnome3.adwaita-icon-theme gsettings-desktop-schemas
    ];
  
    doCheck = true;
  
negative.code: { stdenv
  , fetchurl
  , meson
  , ninja
  , pkgconfig
  , gnome3
  , gtk3
  , wrapGAppsHook
  , glib
  , amtk
  , appstream-glib
  , gobject-introspection
  , python3
  , webkitgtk
  , gettext
  , itstool
  , gsettings-desktop-schemas
  }:
  
  stdenv.mkDerivation rec {
    pname = "devhelp";
  