anchor.diff:  , zlib
   , dbus
   , networkmanager
  +, enableJavaScript ? stdenv.isDarwin || lib.meta.availableOn stdenv.hostPlatform spidermonkey_68
   , spidermonkey_68
   , pcre
   , gsettings-desktop-schemas
  
positive.code:     pcre
      python3
      zlib
    ] ++ (if stdenv.hostPlatform.isDarwin then [
      SystemConfiguration
      CoreFoundation
      JavaScriptCore
    ] else [
      glib
      spidermonkey_68
      dbus
      networkmanager
    ]);
  
    cmakeFlags = [
      "-DWITH_MOZJS=ON"
      "-DWITH_PYTHON2=OFF"
      "-DPYTHON3_SITEPKG_DIR=${placeholder "py3"}/${python3.sitePackages}"
    ];
  
    postFixup = lib.optionalString stdenv.isLinux ''
      # config_gnome3 uses the helper to find GNOME proxy settings
  
negative.code: , JavaScriptCore
  }:
  
  let
    jsRuntime = if stdenv.hostPlatform.isDarwin then JavaScriptCore else spidermonkey_68;
  in stdenv.mkDerivation rec {
    pname = "libproxy";
    version = "0.4.17";
  
  