godot: add a dev output containing the gdnative headers

pkgs/development/tools/godot/default.nix

@@ -34,27 +34,29 @@ in stdenv.mkDerivation rec {
   enableParallelBuilding = true;
 
   buildPhase = ''
-    scons platform=x11 prefix=$out -j $NIX_BUILD_CORES \
+    scons target=release_debug platform=x11 prefix=$out -j $NIX_BUILD_CORES \
       ${lib.concatStringsSep " "
           (lib.mapAttrsToList (k: v: "${k}=${builtins.toJSON v}") options)}
   '';
 
+  outputs = [ "out" "dev" "man" ];
+
   installPhase = ''
-    mkdir -p $out/bin
+    mkdir -p "$out/bin"
-    cp bin/godot.x11.tools.* $out/bin/godot
+    cp bin/godot.* $out/bin/godot
 
-    mkdir -p "$out/share/applications"
+    mkdir "$dev"
+    cp -r modules/gdnative/include $dev
+
+    mkdir -p "$man/share/man/man6"
+    cp misc/dist/linux/godot.6 "$man/share/man/man6/"
+
+    mkdir -p "$out"/share/{applications,icons/hicolor/scalable/apps}
     cp misc/dist/linux/godot.desktop "$out/share/applications/"
-    substituteInPlace "$out/share/applications/godot.desktop" \
-                      --replace "Exec=godot" \
-                      "Exec=$out/bin/godot"
-
-    mkdir -p "$out/share/icons/hicolor/scalable/apps/"
     cp icon.svg "$out/share/icons/hicolor/scalable/apps/godot.svg"
     cp icon.png "$out/share/icons/godot.png"
-
+    substituteInPlace "$out/share/applications/godot.desktop" \
-    mkdir -p "$out/share/man/man6"
+      --replace "Exec=godot" "Exec=$out/bin/godot"
-    cp misc/dist/linux/godot.6 "$out/share/man/man6/"
   '';
 
   meta = {