qttools: patch qmlimportscanner for darwin builds

This needs to be the full path for qtmacdeploy to work. We add
${qt5.qttools.dev}/bin/qmlimportscanner as the default.

Fixes #63093

pkgs/development/libraries/qt-5/5.11/qttools.patch

@@ -69,3 +69,18 @@ index 4318b16f..d60db4ff 100644
      _qt5_LinguistTools_check_file_exists(${imported_location})
  
      set_target_properties(Qt5::lconvert PROPERTIES
+--- a/src/macdeployqt/shared/shared.cpp
++++ b/src/macdeployqt/shared/shared.cpp
+@@ -1241,6 +1241,12 @@ bool deployQmlImports(const QString &appBundlePath, DeploymentInfo deploymentInf
+     if (!QFile(qmlImportScannerPath).exists())
+         qmlImportScannerPath = QCoreApplication::applicationDirPath() + "/qmlimportscanner";
+ 
++#ifdef NIXPKGS_QMLIMPORTSCANNER
++    // Fallback: Nixpkgs hardcoded path
++    if (!QFile(qmlImportScannerPath).exists())
++        qmlImportScannerPath = NIXPKGS_QMLIMPORTSCANNER;
++#endif
++
+     // Verify that we found a qmlimportscanner binary
+     if (!QFile(qmlImportScannerPath).exists()) {
+         LogError() << "qmlimportscanner not found at" << qmlImportScannerPath;

pkgs/development/libraries/qt-5/5.12/default.nix

@@ -66,6 +66,7 @@ let
         ./qtwebkit-darwin-no-readline.patch
         ./qtwebkit-darwin-no-qos-classes.patch
       ];
+    qttools = [ ./qttools.patch ];
   };
 
   mkDerivation =

pkgs/development/libraries/qt-5/5.12/qttools.patch

@@ -0,0 +1,15 @@
+--- a/src/macdeployqt/shared/shared.cpp
++++ b/src/macdeployqt/shared/shared.cpp
+@@ -1241,6 +1241,12 @@ bool deployQmlImports(const QString &appBundlePath, DeploymentInfo deploymentInf
+     if (!QFile(qmlImportScannerPath).exists())
+         qmlImportScannerPath = QCoreApplication::applicationDirPath() + "/qmlimportscanner";
+ 
++#ifdef NIXPKGS_QMLIMPORTSCANNER
++    // Fallback: Nixpkgs hardcoded path
++    if (!QFile(qmlImportScannerPath).exists())
++        qmlImportScannerPath = NIXPKGS_QMLIMPORTSCANNER;
++#endif
++
+     // Verify that we found a qmlimportscanner binary
+     if (!QFile(qmlImportScannerPath).exists()) {
+         LogError() << "qmlimportscanner not found at" << qmlImportScannerPath;

pkgs/development/libraries/qt-5/modules/qttools.nix

@@ -1,4 +1,4 @@
-{ qtModule, stdenv, lib, qtbase }:
+{ qtModule, stdenv, lib, qtbase, qtdeclarative }:
 
 with lib;
 
@@ -32,5 +32,8 @@ qtModule {
     "bin/macdeployqt"
   ];
 
+  NIX_CFLAGS_COMPILE =
+    lib.optional stdenv.isDarwin ''-DNIXPKGS_QMLIMPORTSCANNER="${qtdeclarative.dev}/bin/qmlimportscanner"'';
+
   setupHook = ../hooks/qttools-setup-hook.sh;
 }