vte-gtk4: init

pkgs/development/libraries/vte/default.nix

···
 , gnome
 , glib
 , gtk3
+, gtk4
+, gtkVersion ? "3"
 , gobject-introspection
 , vala
 , python3
···
     systemd
   ];
 
-  propagatedBuildInputs = [
+  propagatedBuildInputs = assert (gtkVersion == "3" || gtkVersion == "4"); [
     # Required by vte-2.91.pc.
-    gtk3
+    (if gtkVersion == "3" then gtk3 else gtk4)
     glib
     pango
   ];
 
   mesonFlags = lib.optionals (!systemdSupport) [
     "-D_systemd=false"
+  ] ++ lib.optionals (gtkVersion == "4") [
+    "-Dgtk3=false"
+    "-Dgtk4=true"
   ] ++ lib.optionals stdenv.isDarwin [
     # -Bsymbolic-functions is not supported on darwin
     "-D_b_symbolic_functions=false"

pkgs/top-level/all-packages.nix

···
     stdenv = clangStdenv;
   };
 
+  vte-gtk4 = vte.override {
+    gtkVersion = "4";
+  };
+
   vte_290 = callPackage ../development/libraries/vte/2.90.nix { };
 
   vtk_8 = libsForQt515.callPackage ../development/libraries/vtk/8.x.nix {