Pin qt6 package version to 6.6.3

Currently, this succesfully launches the program. Pinning qt seperatly
allows the rest of unstable nixpkgs to be updated even after the qt
package version has been bumped. This fixes vim failing to launch in the
nix shell because of a bad gcc version. Bumping the package version to
qt6.7.1 also will require bumping PySide to 6.7.1, otherwise it will
fail to find qt. Qt 6.7.1 nixpkg commit is 47da0aee5616a063015f10ea593688646f2377e4

Author: seakrueger

flake.lock

@@ -1,9 +1,18 @@
 {
-  inputs.nixpkgs.url = "github:nixos/nixpkgs/nixos-unstable";
+  inputs = {
+    nixpkgs.url = "github:nixos/nixpkgs/nixos-unstable";
 
-  outputs = { self, nixpkgs, }:
+    qt6Pkgs = {
+      # Commit bumping to qt6.6.3
+      url = "github:NixOS/nixpkgs/f862bd46d3020bcfe7195b3dad638329271b0524"; 
+    };
+  };
+
+  outputs = { self, nixpkgs, qt6Pkgs }:
   let
     pkgs = nixpkgs.legacyPackages.x86_64-linux;
+
+    qt6 = qt6Pkgs.legacyPackages.x86_64-linux.qt6;
   in {
     devShells.x86_64-linux.default = pkgs.mkShell {
       LD_LIBRARY_PATH = pkgs.lib.makeLibraryPath [
@@ -17,22 +26,19 @@
         pkgs.xorg.libxcb
         pkgs.freetype
         pkgs.dbus
-        pkgs.qt6.qtwayland
-        pkgs.qt6.full
-        pkgs.qt6.qtbase
         pkgs.zstd
         # For PySide6 Multimedia
         pkgs.libpulseaudio
         pkgs.libkrb5
+
+        qt6.qtwayland
+        qt6.full
+        qt6.qtbase
       ];
       buildInputs = with pkgs; [
         cmake
         gdb
         zstd
-        qt6.qtbase
-        qt6.full
-        qt6.qtwayland
-        qtcreator
         python312Packages.pip
         python312Full
         python312Packages.virtualenv # run virtualenv .
@@ -52,11 +58,17 @@
         fontconfig
         xorg.libxcb
 
-
         # this is for the shellhook portion
-        qt6.wrapQtAppsHook
         makeWrapper
         bashInteractive
+      ] ++ [
+        qt6.qtbase
+        qt6.full
+        qt6.qtwayland
+        qtcreator
+
+        # this is for the shellhook portion
+        qt6.wrapQtAppsHook
       ];
       # set the environment variables that Qt apps expect
       shellHook = ''