From dc2e4ebdec4da496cff480eac05edf63ef00a853 Mon Sep 17 00:00:00 2001
From: K900 <me@0upti.me>
Date: Thu, 18 Sep 2025 23:13:58 +0300
Subject: [PATCH 1/3] qt6.qttools: pin LLVM 20

Qt 6.9 doesn't support LLVM 21.
---
 .../development/libraries/qt-6/modules/qttools/default.nix | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/pkgs/development/libraries/qt-6/modules/qttools/default.nix b/pkgs/development/libraries/qt-6/modules/qttools/default.nix
index fd68b6fd087e..48d36780fea6 100644
--- a/pkgs/development/libraries/qt-6/modules/qttools/default.nix
+++ b/pkgs/development/libraries/qt-6/modules/qttools/default.nix
@@ -6,16 +6,17 @@
   qtbase,
   qtdeclarative,
   cups,
-  llvmPackages,
+  llvmPackages_20,
   # clang-based c++ parser for qdoc and lupdate
   withClang ? false,
 }:
 
 qtModule {
   pname = "qttools";
+  # FIXME: update to LLVM 21 with Qt 6.10
   buildInputs = lib.optionals withClang [
-    llvmPackages.libclang
-    llvmPackages.llvm
+    llvmPackages_20.libclang
+    llvmPackages_20.llvm
   ];
   propagatedBuildInputs = [
     qtbase

From d086eee1fc083fbf04b5dc236b5808e4a42666f0 Mon Sep 17 00:00:00 2001
From: K900 <me@0upti.me>
Date: Thu, 18 Sep 2025 23:14:37 +0300
Subject: [PATCH 2/3] qt6.qttools: clean up

---
 .../qt-6/modules/qttools/default.nix          | 45 ++++++++++++-------
 1 file changed, 28 insertions(+), 17 deletions(-)

diff --git a/pkgs/development/libraries/qt-6/modules/qttools/default.nix b/pkgs/development/libraries/qt-6/modules/qttools/default.nix
index 48d36780fea6..4fb69db29359 100644
--- a/pkgs/development/libraries/qt-6/modules/qttools/default.nix
+++ b/pkgs/development/libraries/qt-6/modules/qttools/default.nix
@@ -13,26 +13,11 @@
 
 qtModule {
   pname = "qttools";
-  # FIXME: update to LLVM 21 with Qt 6.10
-  buildInputs = lib.optionals withClang [
-    llvmPackages_20.libclang
-    llvmPackages_20.llvm
-  ];
-  propagatedBuildInputs = [
-    qtbase
-    qtdeclarative
-  ]
-  ++ lib.optionals stdenv.hostPlatform.isDarwin [ cups ];
-  cmakeFlags = lib.optionals (!stdenv.buildPlatform.canExecute stdenv.hostPlatform) [
-    "-DQt6LinguistTools_DIR=${pkgsBuildBuild.qt6.qttools}/lib/cmake/Qt6LinguistTools"
-    "-DQt6ToolsTools_DIR=${pkgsBuildBuild.qt6.qttools}/lib/cmake/Qt6ToolsTools"
-  ];
+
   patches = [
     ./paths.patch
   ];
-  env.NIX_CFLAGS_COMPILE = toString [
-    "-DNIX_OUTPUT_OUT=\"${placeholder "out"}\""
-  ];
+
   postPatch = ''
     substituteInPlace \
       src/qdoc/catch/CMakeLists.txt \
@@ -40,6 +25,32 @@ qtModule {
       src/qdoc/catch_conversions/CMakeLists.txt \
       --replace ''\'''${CMAKE_INSTALL_INCLUDEDIR}' "$out/include"
   '';
+
+  env.NIX_CFLAGS_COMPILE = toString [
+    "-DNIX_OUTPUT_OUT=\"${placeholder "out"}\""
+  ];
+
+  # FIXME: update to LLVM 21 with Qt 6.10
+  buildInputs = lib.optionals withClang [
+    llvmPackages_20.libclang
+    llvmPackages_20.llvm
+  ];
+
+  propagatedBuildInputs = [
+    qtbase
+    qtdeclarative
+  ]
+  ++ lib.optionals stdenv.hostPlatform.isDarwin [ cups ];
+
+  cmakeFlags =
+    lib.optionals (!stdenv.buildPlatform.canExecute stdenv.hostPlatform) [
+      "-DQt6LinguistTools_DIR=${pkgsBuildBuild.qt6.qttools}/lib/cmake/Qt6LinguistTools"
+      "-DQt6ToolsTools_DIR=${pkgsBuildBuild.qt6.qttools}/lib/cmake/Qt6ToolsTools"
+    ]
+    ++ lib.optionals withClang [
+      "-DFEATURE_clang=ON"
+    ];
+
   postInstall = ''
     mkdir -p "$dev"
     ln -s "$out/bin" "$dev/bin"

From bcc0e083718215beecebb50df8ab8c36040b5b46 Mon Sep 17 00:00:00 2001
From: K900 <me@0upti.me>
Date: Thu, 18 Sep 2025 22:25:58 +0300
Subject: [PATCH 3/3] qt6.qtdoc: clean up

---
 pkgs/development/libraries/qt-6/modules/qtdoc.nix | 11 +++--------
 1 file changed, 3 insertions(+), 8 deletions(-)

diff --git a/pkgs/development/libraries/qt-6/modules/qtdoc.nix b/pkgs/development/libraries/qt-6/modules/qtdoc.nix
index fa091d4c6da6..5e35b4b5d5fb 100644
--- a/pkgs/development/libraries/qt-6/modules/qtdoc.nix
+++ b/pkgs/development/libraries/qt-6/modules/qtdoc.nix
@@ -16,12 +16,7 @@ qtModule {
   '';
   nativeBuildInputs = [ (qttools.override { withClang = true; }) ];
   propagatedBuildInputs = [ qtdeclarative ];
-  cmakeFlags = [
-    "-DCMAKE_MESSAGE_LOG_LEVEL=STATUS"
-  ];
-  dontUseNinjaBuild = true;
-  buildFlags = [ "docs" ];
-  dontUseNinjaInstall = true;
-  installFlags = [ "install_docs" ];
-  outputs = [ "out" ];
+
+  ninjaFlags = [ "docs" ];
+  installTargets = [ "install_docs" ];
 }