mmlgui: migrate to by-name (#492532)

pkgs/by-name/mm/mmlgui/package.nix

@@ -11,7 +11,15 @@
   libxdmcp,
   cppunit,
 }:
-
+let
+  libvgm' = libvgm.override {
+    withAllEmulators = false;
+    emulators = [
+      "_PRESET_SMD"
+    ];
+    enableLibplayer = false;
+  };
+in
 stdenv.mkDerivation {
   pname = "mmlgui";
   version = "210420-preview-unstable-2026-01-09";
@@ -52,7 +60,7 @@ stdenv.mkDerivation {
 
   buildInputs = [
     glfw
-    libvgm
+    libvgm'
   ]
   ++ lib.optionals stdenv.hostPlatform.isLinux [
     libx11

pkgs/top-level/all-packages.nix

@@ -10099,16 +10099,6 @@ with pkgs;
     ocamlPackages = ocaml-ng.ocamlPackages_4_14;
   };
 
-  mmlgui = callPackage ../applications/audio/mmlgui {
-    libvgm = libvgm.override {
-      withAllEmulators = false;
-      emulators = [
-        "_PRESET_SMD"
-      ];
-      enableLibplayer = false;
-    };
-  };
-
   monotone = callPackage ../applications/version-management/monotone {
     lua = lua5;
   };