@@ -6,27 +6,22 @@ on:
     - cron: '0 0 1 * *'
 
 jobs:
-  build:
+  build-linux:
+    name: >
+      build-linux (python-${{ matrix.python-version }}, ${{ matrix.compiler }})
     runs-on: ${{ matrix.os }}
     strategy:
       matrix:
-        os: [ubuntu-latest, windows-latest, macos-latest]
+        os: [ubuntu-latest]
         python-version: ['3.9', '3.10', '3.11', '3.12', '3.13']
-        compiler: [default]
+        compiler: [gcc]
 
         include:
-          - {os: ubuntu-latest, extra-tests: [mingw-cross],
+          - {os: ubuntu-latest, compiler: gcc, extra-tests: [mingw-cross],
              backends: [ninja, make], flags: -Wall -Werror}
-          - {os: windows-latest, msvc-version: '14.4', win-sdk: '10.0.26100.0',
-             boost-version: '1.80.0', qt-version: '5.15.2',
-             skipped-tests: [fortran, objc, scala],
-             backends: [ninja, make, msbuild], flags: /WX}
-          - {os: macos-latest, skipped-tests: [scala], backends: [ninja, make],
-             flags: -Wall -Werror -Wno-deprecated-declarations
-               -DGL_SILENCE_DEPRECATION, cxxflags: -std=c++11}
 
           # Old Python builds
-          - {os: ubuntu-24.04, python-version: '3.8', compiler: default,
+          - {os: ubuntu-24.04, python-version: '3.8', compiler: gcc,
              backends: [ninja, make], flags: -Wall -Werror}
 
           # Clang builds
@@ -42,6 +37,79 @@ jobs:
           # - {os: ubuntu-16.04, python-version: '3.13', compiler: default,
           #    extra-packages: [gcj-4.9, gcj-4.9-jdk],
           #    extra-tests: [mingw-cross, gcj], backends: [ninja, make]}
+      fail-fast: false
+    env: &default-env
+      # GCJ: gcj-4.9
+      BACKENDS: ${{ join(matrix.backends, ' ') }}
+      BFG_EXTRA_TESTS: ${{ join(matrix.extra-tests, ' ') }}
+      BFG_SKIPPED_TESTS: ${{ join(matrix.skipped-tests, ' ') }}
+      CPPFLAGS: ${{ matrix.flags }}
+      CXXFLAGS: ${{ matrix.cxxflags }}
+
+    steps:
+      - uses: actions/checkout@v4
+      - name: Set up Python ${{ matrix.python-version }}
+        uses: actions/setup-python@v5
+        with:
+          python-version: ${{ matrix.python-version }}
+      - name: Install Python dependencies
+        run: |
+          pip install git+https://github.com/jimporter/mopack.git '.[test]'
+      - name: Install Linux dependencies
+        run: >
+          sudo add-apt-repository ppa:ubuntu-toolchain-r/test &&
+          sudo apt-get update &&
+          sudo apt-get install
+          bison
+          default-jdk
+          flex
+          freeglut3-dev
+          gcc-multilib
+          gfortran
+          gobjc++
+          libboost-dev
+          libboost-program-options-dev
+          libgl1-mesa-dev
+          libogg-dev
+          mingw-w64
+          ninja-build
+          patchelf
+          qtbase5-dev
+          qtbase5-dev-tools
+          qtchooser
+          qtdeclarative5-dev
+          qt5-qmake
+          scala
+          ${{ join(matrix.extra-packages, ' ') }}
+      - name: Set up clang
+        if: matrix.compiler == 'clang'
+        run: |
+          echo "CC=clang" >> ${GITHUB_ENV}
+          echo "CXX=clang++" >> ${GITHUB_ENV}
+      - name: Run tests
+        run: |
+          python setup.py coverage -q
+          coverage xml
+      - name: Upload coverage
+        uses: codecov/codecov-action@v3
+        with:
+          files: ./coverage.xml
+
+  build-windows:
+    name: >
+      build-windows (python-${{ matrix.python-version }}, ${{ matrix.compiler }})
+    runs-on: ${{ matrix.os }}
+    strategy:
+      matrix:
+        os: [windows-latest]
+        python-version: ['3.9', '3.10', '3.11', '3.12', '3.13']
+        compiler: [msvc]
+
+        include:
+          - {os: windows-latest, msvc-version: '14.4', win-sdk: '10.0.26100.0',
+             boost-version: '1.80.0', qt-version: '5.15.2',
+             skipped-tests: [fortran, objc, scala],
+             backends: [ninja, make, msbuild], flags: /WX}
 
           # VS 2015 builds
           # FIXME: Currently disabled, since Github retired these images.
@@ -66,7 +134,7 @@ jobs:
           #    backends: [ninja, make, msbuild], flags: /WX}
 
           # VS 2022 x86 builds
-          - {os: windows-latest, python-version: '3.13', compiler: default-x86,
+          - {os: windows-latest, python-version: '3.13', compiler: msvc-x86,
              msvc-version: '14.4', msvc-arch: 'x86', win-sdk: '10.0.26100.0',
              boost-version: '1.80.0', skipped-tests: [fortran, objc, qt, scala],
              backends: [ninja, make, msbuild], flags: /WX}
@@ -78,26 +146,12 @@ jobs:
              skipped-tests: [boost, fortran, objc, scala],
              backends: [ninja, make], flags: /WX -Wno-microsoft-include
                -Wno-unused-command-line-argument -D_CRT_SECURE_NO_WARNINGS}
-
-          # MinGW builds
-          - {os: windows-2022, python-version: '3.13', compiler: mingw,
-             msvc-version: '14.4', win-sdk: '10.0.19041.0',
-             qt-version: '5.15.2', qt-arch: 'win64_mingw81',
-             skipped-tests: [boost, fortran, objc, pch, scala],
-             backends: [ninja, make], flags: -Wall -Werror}
       fail-fast: false
-    env:
-      GCJ: gcj-4.9
-      BACKENDS: ${{ join(matrix.backends, ' ') }}
-      BFG_EXTRA_TESTS: ${{ join(matrix.extra-tests, ' ') }}
-      BFG_SKIPPED_TESTS: ${{ join(matrix.skipped-tests, ' ') }}
-      CPPFLAGS: ${{ matrix.flags }}
-      CXXFLAGS: ${{ matrix.cxxflags }}
+    env: *default-env
 
     steps:
       - uses: actions/checkout@v4
       - name: Cache Boost binaries
-        if: startsWith(matrix.os, 'windows-') && matrix.boost-version
         uses: actions/cache@v4
         id: cache-boost
         with:
@@ -115,7 +169,7 @@ jobs:
         run: |
           pip install git+https://github.com/jimporter/mopack.git '.[test]'
       - name: Initialize MSVC ${{ matrix.msvc-version }}
-        if: startsWith(matrix.os, 'windows-')
+        if: startsWith(matrix.os, 'windows-') && matrix.compiler != 'mingw'
         uses: ilammy/msvc-dev-cmd@v1
         with:
           toolset: ${{ matrix.msvc-version }}
@@ -128,7 +182,6 @@ jobs:
           version: ${{ matrix.qt-version }}
           arch: ${{ matrix.qt-arch }}
       - name: Install Boost ${{ matrix.boost-version }} from binaries
-        if: startsWith(matrix.os, 'windows-') && matrix.boost-version
         run: |
           ${boostroot} = "C:\boost-${{ matrix.boost-version }}"
           ${msvcver} = "${{ matrix.msvc-version }}" -replace '14.4','14.3'
@@ -141,35 +194,7 @@ jobs:
           }
           echo "BOOST_INCLUDEDIR=${boostroot}" >> ${env:GITHUB_ENV}
           echo "BOOST_LIBRARYDIR=${boostroot}\lib${arch}-msvc-${msvcver}" >> ${env:GITHUB_ENV}
-      - name: Install Linux dependencies
-        if: startsWith(matrix.os, 'ubuntu-')
-        run: >
-          sudo add-apt-repository ppa:ubuntu-toolchain-r/test &&
-          sudo apt-get update &&
-          sudo apt-get install
-          bison
-          default-jdk
-          flex
-          freeglut3-dev
-          gcc-multilib
-          gfortran
-          gobjc++
-          libboost-dev
-          libboost-program-options-dev
-          libgl1-mesa-dev
-          libogg-dev
-          mingw-w64
-          ninja-build
-          patchelf
-          qtbase5-dev
-          qtbase5-dev-tools
-          qtchooser
-          qtdeclarative5-dev
-          qt5-qmake
-          scala
-          ${{ join(matrix.extra-packages, ' ') }}
       - name: Install Windows dependencies
-        if: startsWith(matrix.os, 'windows-')
         run: |
           choco install ninja pkgconfiglite winflexbison3
 
@@ -197,39 +222,105 @@ jobs:
           echo "CPPFLAGS=-I${pwd}\include ${env:CPPFLAGS}" >> ${env:GITHUB_ENV}
           echo "LIBRARY_PATH=${env:LIBRARY_PATH};${pwd}\lib" >> ${env:GITHUB_ENV}
           echo "PATH=${env:PATH};${pwd}\lib" >> ${env:GITHUB_ENV}
+      - name: Set up clang-cl
+        if: matrix.compiler == 'clang-cl'
+        run: |
+          echo "CC=clang-cl" >> ${env:GITHUB_ENV}
+          echo "CXX=clang-cl" >> ${env:GITHUB_ENV}
+      - name: Run tests
+        run: |
+          python setup.py coverage -q
+          coverage xml
+      - name: Upload coverage
+        uses: codecov/codecov-action@v3
+        with:
+          files: ./coverage.xml
+
+  build-macos:
+    name: >
+      build-macos (python-${{ matrix.python-version }}, ${{ matrix.compiler }})
+    runs-on: ${{ matrix.os }}
+    strategy:
+      matrix:
+        os: [macos-latest]
+        python-version: ['3.9', '3.10', '3.11', '3.12', '3.13']
+        compiler: [clang]
+
+        include:
+          - {os: macos-latest, skipped-tests: [scala], backends: [ninja, make],
+             flags: -Wall -Werror -Wno-deprecated-declarations
+               -DGL_SILENCE_DEPRECATION, cxxflags: -std=c++11}
+      fail-fast: false
+    env: *default-env
+
+    steps:
+      - uses: actions/checkout@v4
+      - name: Set up Python ${{ matrix.python-version }}
+        uses: actions/setup-python@v5
+        with:
+          python-version: ${{ matrix.python-version }}
+      - name: Install Python dependencies
+        run: |
+          pip install git+https://github.com/jimporter/mopack.git '.[test]'
       - name: Install macOS dependencies
-        if: startsWith(matrix.os, 'macos-')
         run: |
           brew install bison boost libogg ninja pkg-config qt5
           brew link qt5 --force
           echo "FC=gfortran-14" >> ${GITHUB_ENV}
           echo "YACC=/opt/homebrew/opt/bison/bin/bison" >> ${GITHUB_ENV}
           echo "CPATH=/opt/homebrew/include" >> ${GITHUB_ENV}
           echo "LIBRARY_PATH=/opt/homebrew/lib" >> ${GITHUB_ENV}
-      - name: Set up clang
-        if: matrix.compiler == 'clang'
-        run: |
-          echo "CC=clang" >> ${GITHUB_ENV}
-          echo "CXX=clang++" >> ${GITHUB_ENV}
-      - name: Set up clang-cl
-        if: matrix.compiler == 'clang-cl'
+      - name: Run tests
         run: |
-          echo "CC=clang-cl" >> ${env:GITHUB_ENV}
-          echo "CXX=clang-cl" >> ${env:GITHUB_ENV}
-      - name: Set up mingw
-        if: matrix.compiler == 'mingw'
+          python setup.py coverage -q
+          coverage xml
+      - name: Upload coverage
+        uses: codecov/codecov-action@v3
+        with:
+          files: ./coverage.xml
+
+  build-mingw:
+    runs-on: windows-latest
+    defaults:
+      run:
+        shell: msys2 {0}
+    strategy:
+      matrix:
+        include:
+          - {os: windows-latest, qt-version: '5.15.2', qt-arch: 'win64_mingw81',
+             skipped-tests: [boost, fortran, objc, pch, scala],
+             backends: [ninja, make], flags: -Wall -Werror}
+    env: *default-env
+
+    steps:
+      - uses: actions/checkout@v4
+      - uses: msys2/setup-msys2@v2
+        with:
+          msystem: UCRT64
+          update: true
+          install: >
+            git
+            mingw-w64-ucrt-x86_64-make
+            mingw-w64-ucrt-x86_64-ninja
+            mingw-w64-ucrt-x86_64-python-pip
+            mingw-w64-ucrt-x86_64-python-lxml
+            mingw-w64-ucrt-x86_64-gcc
+      - name: Install Python dependencies
         run: |
-          echo "PATH=C:\msys64\mingw64\bin;${env:PATH}" >> ${env:GITHUB_ENV}
-          echo "CC=gcc" >> ${env:GITHUB_ENV}
-          echo "CXX=g++" >> ${env:GITHUB_ENV}
+          python -m venv .venv --system-site-packages
+          . .venv/bin/activate
+          pip install git+https://github.com/jimporter/mopack.git '.[test]'
       - name: Run tests
         run: |
+          . .venv/bin/activate
+          export MAKE=mingw32-make
           python setup.py coverage -q
           coverage xml
       - name: Upload coverage
         uses: codecov/codecov-action@v3
         with:
           files: ./coverage.xml
+
   build-cygwin:
     runs-on: windows-latest
     env:
@@ -267,6 +358,7 @@ jobs:
         uses: codecov/codecov-action@v3
         with:
           files: ./coverage.xml
+
   bdist-wheel:
     runs-on: ubuntu-latest
 
@@ -282,6 +374,7 @@ jobs:
           python setup.py bdist_wheel
           pip install dist/*.whl
           ! pip show pysetenv
+
   lint:
     runs-on: ubuntu-latest