Update Github Actions workflows for Qt6

* Update MacOS test builds to test both Qt5 and Qt6. However, due to
  Homebrew/brew#15354, macdeployqt is still
  broken for Qt6 on Homebrew, so MacOS release builds will continue to
  use Qt5 instead.
* Update Windows test builds to test Qt5 for i686 and Qt6 for x86_64
* Update Windows release build to use MinGW. This more closely matches
  the Qt builds and partially reverts 7cab5e2.
* Update Windows release build to use Qt6
* Update README to mention CMAKE_PREFIX_PATH because this appears to be
  necessary for Windows release builds that use a standalone Qt
  installation

.github/workflows/macos-build.yaml

@@ -20,9 +20,11 @@ jobs:
         include:
           - { name: "MacOS 11", os: macos-11, osx_arch: "x86_64;arm64", build_type: "Release", deps: "none", fetch_deps: YES, build_dukpt_ui: NO }
           - { name: "MacOS 11", os: macos-11, osx_arch: "x86_64;arm64", build_type: "Debug", deps: "tr31", fetch_deps: YES, build_dukpt_ui: NO }
-          - { name: "MacOS 11", os: macos-11, osx_arch: "x86_64", build_type: "Release", deps: "tr31/qt", fetch_deps: NO, build_dukpt_ui: YES }
+          - { name: "MacOS 11", os: macos-11, osx_arch: "x86_64", build_type: "Debug", deps: "tr31/qt5", fetch_deps: NO, build_dukpt_ui: YES }
+          - { name: "MacOS 11", os: macos-11, osx_arch: "x86_64", build_type: "Release", deps: "tr31/qt6", fetch_deps: NO, build_dukpt_ui: YES }
           - { name: "MacOS 12", os: macos-12, osx_arch: "x86_64", build_type: "Release", deps: "tr31", fetch_deps: NO, build_dukpt_ui: NO }
-          - { name: "MacOS 12", os: macos-12, osx_arch: "x86_64", build_type: "Debug", deps: "tr31/qt", fetch_deps: YES, build_dukpt_ui: YES }
+          - { name: "MacOS 12", os: macos-12, osx_arch: "x86_64", build_type: "Debug", deps: "tr31/qt5", fetch_deps: YES, build_dukpt_ui: YES }
+          - { name: "MacOS 12", os: macos-12, osx_arch: "x86_64", build_type: "Debug", deps: "tr31/qt6", fetch_deps: YES, build_dukpt_ui: YES }
 
     name: ${{ matrix.name }} (${{ matrix.osx_arch }}) build (static/${{ matrix.build_type }}/${{ matrix.deps }})
     runs-on: ${{ matrix.os }}
@@ -44,11 +46,18 @@ jobs:
 
     - name: Install Qt5 using brew
       # Homebrew doesn't support universal binaries so only install Qt for x86_64 builds
-      if: contains(matrix.deps, 'qt')
+      if: contains(matrix.deps, 'qt5')
       run: |
         brew install qt@5
         echo "QT_DIR=$(brew --prefix qt@5)/lib/cmake/Qt5" >> $GITHUB_ENV
 
+    - name: Install Qt6 using brew
+      # Homebrew doesn't support universal binaries so only install Qt for x86_64 builds
+      if: contains(matrix.deps, 'qt6')
+      run: |
+        brew install qt@6
+        echo "QT_DIR=$(brew --prefix qt@6)/lib/cmake/Qt6" >> $GITHUB_ENV
+
     - name: Checkout
       uses: actions/checkout@v3
       with:

.github/workflows/windows-build.yaml

@@ -60,10 +60,17 @@ jobs:
         echo "CMAKE_REQUIRE_FIND_PACKAGE_MbedTLS=YES" >> $GITHUB_ENV
 
     - name: Install Qt5
-      if: contains(matrix.deps, 'qt')
+      # MSYS2 doesn't support Qt6 for i686
+      if: ${{ contains(matrix.deps, 'qt') && matrix.env == 'i686' }}
       run: |
         pacman --noconfirm -S --needed mingw-w64-${{matrix.env}}-qt5-base mingw-w64-${{matrix.env}}-qt5-tools
 
+    - name: Install Qt6
+      # MSYS2 doesn't support Qt6 for i686
+      if: ${{ contains(matrix.deps, 'qt') && matrix.env != 'i686' }}
+      run: |
+        pacman --noconfirm -S --needed mingw-w64-${{matrix.env}}-qt6-base mingw-w64-${{matrix.env}}-qt6-tools
+
     - name: Build TR-31 dependency
       if: contains(matrix.deps, 'tr31')
       run: |
@@ -100,7 +107,7 @@ jobs:
       fail-fast: false
       matrix:
         include:
-          - { sys: ucrt64, env: ucrt-x86_64, build_type: "RelWithDebInfo" }
+          - { sys: mingw64, env: x86_64, build_type: "RelWithDebInfo" }
 
     name: Windows MSYS2 ${{matrix.sys}} build (release)
 
@@ -129,14 +136,14 @@ jobs:
           mingw-w64-${{matrix.env}}-github-cli
           mingw-w64-${{matrix.env}}-nsis
 
-    - name: Install Qt
+    - name: Install Qt6
       uses: jurplel/install-qt-action@v3
       with:
-        version: 5.15.*
+        version: 6.5.*
         host: windows
         target: desktop
-        arch: win64_mingw81
-        archives: qtbase qttools
+        arch: win64_mingw
+        archives: qtbase qttools MinGW
 
     - name: Build TR-31 dependency
       run: |
@@ -160,7 +167,7 @@ jobs:
       run: cmake -G Ninja -B build -DCMAKE_BUILD_TYPE="${{ matrix.build_type }}" -DBUILD_SHARED_LIBS=YES -DFETCH_MBEDTLS=YES -DFETCH_ARGP=YES -DBUILD_DUKPT_UI=YES -Dtr31_DIR=${{ env.TR31_DIR }}
       # CMake will only accept Windows paths if they are environment variables, not CMake command line cache entries
       env:
-        QT_DIR: ${{ env.Qt5_DIR }}
+        CMAKE_PREFIX_PATH: ${{ env.Qt6_DIR }}
 
     - name: Build
       run: cmake --build build

README.md

@@ -159,9 +159,10 @@ Qt
 This project supports Qt 5.12.x, Qt 5.15.x and Qt 6.5.x (although it may be
 possible to use other versions of Qt) when building the `dukpt-ui` application.
 However, on some platforms it may be necessary to use the `QT_DIR` option (and
-not the `Qt5_DIR` nor `Qt6_DIR` options) to specify the exact Qt installation
-to be used. For Qt6 it may also be necessary for the Qt tools to be available
-in the executable PATH regardless of the `QT_DIR` option.
+not the `Qt5_DIR` nor `Qt6_DIR` options) or `CMAKE_PREFIX_PATH` option to
+specify the exact Qt installation to be used. For Qt6 it may also be necessary
+for the Qt tools to be available in the executable PATH regardless of the
+`QT_DIR` option.
 
 If the Qt installation does not provide universal binaries for MacOS, it will
 not be possible to build `dukpt-ui` as a universal binary for MacOS.