Fix Qt6 building (#4393)

.github/workflows/build.yml

@@ -15,6 +15,7 @@ concurrency:
 env:
   C2_ENABLE_LTO: ${{ github.ref == 'refs/heads/master' }}
   CHATTERINO_REQUIRE_CLEAN_GIT: On
+  C2_BUILD_WITH_QT6: Off
 
 jobs:
   build:
@@ -39,6 +40,11 @@ jobs:
             qt-version: 5.15.2
             pch: true
             force-lto: false
+          # Ubuntu 22.04, Qt 6.2.4
+          - os: ubuntu-22.04
+            qt-version: 6.2.4
+            pch: false
+            force-lto: false
           # Test for disabling Precompiled Headers & enabling link-time optimization
           - os: ubuntu-22.04
             qt-version: 5.15.2
@@ -73,18 +79,34 @@ jobs:
           echo "vs_version=2022" >> "$GITHUB_ENV"
         shell: bash
 
+      - name: Set BUILD_WITH_QT6
+        if: startsWith(matrix.qt-version, '6.')
+        run: |
+          echo "C2_BUILD_WITH_QT6=ON" >> "$GITHUB_ENV"
+        shell: bash
+
       - uses: actions/checkout@v3
         with:
           submodules: recursive
           fetch-depth: 0 # allows for tags access
 
-      - name: Install Qt
+      - name: Install Qt5
+        if: startsWith(matrix.qt-version, '5.')
         uses: jurplel/install-qt-action@v3.0.0
         with:
           cache: true
           cache-key-prefix: ${{ runner.os }}-QtCache-${{ matrix.qt-version }}-v2
           version: ${{ matrix.qt-version }}
 
+      - name: Install Qt6
+        if: startsWith(matrix.qt-version, '6.')
+        uses: jurplel/install-qt-action@v3.0.0
+        with:
+          cache: true
+          cache-key-prefix: ${{ runner.os }}-QtCache-${{ matrix.qt-version }}-v2
+          modules: qt5compat
+          version: ${{ matrix.qt-version }}
+
       # WINDOWS
       - name: Cache conan packages part 1
         if: startsWith(matrix.os, 'windows')
@@ -131,6 +153,7 @@ jobs:
               -DCMAKE_TOOLCHAIN_FILE="conan_toolchain.cmake" `
               -DBUILD_WITH_CRASHPAD="$Env:C2_ENABLE_CRASHPAD" `
               -DCHATTERINO_LTO="$Env:C2_ENABLE_LTO" `
+              -DBUILD_WITH_QT6="$Env:C2_BUILD_WITH_QT6" `
               ..
           set cl=/MP
           nmake /S /NOLOGO
@@ -216,6 +239,7 @@ jobs:
             -DUSE_PRECOMPILED_HEADERS=${{ matrix.pch }} \
             -DCMAKE_EXPORT_COMPILE_COMMANDS=On \
             -DCHATTERINO_LTO="$C2_ENABLE_LTO" \
+            -DBUILD_WITH_QT6="$C2_BUILD_WITH_QT6" \
             ..
           make -j"$(nproc)"
         shell: bash
@@ -284,6 +308,7 @@ jobs:
               -DOPENSSL_ROOT_DIR=/usr/local/opt/openssl \
               -DUSE_PRECOMPILED_HEADERS=${{ matrix.pch }} \
               -DCHATTERINO_LTO="$C2_ENABLE_LTO" \
+              -DBUILD_WITH_QT6="$C2_BUILD_WITH_QT6" \
               ..
           make -j"$(sysctl -n hw.logicalcpu)"
         shell: bash