Test 3.13 free-threaded build on CI

.ci/install.sh

@@ -37,12 +37,14 @@ python3 -m pip install -U pytest-timeout
 python3 -m pip install pyroma
 
 if [[ $(uname) != CYGWIN* ]]; then
-    python3 -m pip install numpy
+    # TODO Update condition when NumPy supports free-threading
+    if ! [[ "$GHA_PYTHON_VERSION" == "3.13-dev" ]]; then python3 -m pip install numpy ; fi
 
     # PyQt6 doesn't support PyPy3
     if [[ $GHA_PYTHON_VERSION == 3.* ]]; then
         sudo apt-get -qq install libegl1 libxcb-cursor0 libxcb-icccm4 libxcb-image0 libxcb-keysyms1 libxcb-randr0 libxcb-render-util0 libxcb-shape0 libxkbcommon-x11-0
-        python3 -m pip install pyqt6
+        # TODO Update condition when pyqt6 supports free-threading
+        if ! [[ "$GHA_PYTHON_VERSION" == "3.13-dev" ]]; then python3 -m pip install pyqt6 ; fi
     fi
 
     # Pyroma uses non-isolated build and fails with old setuptools

.github/workflows/test.yml

@@ -55,6 +55,8 @@ jobs:
           REVERSE: "--reverse"
         - python-version: "3.10"
           PYTHONOPTIMIZE: 2
+        # Free-threaded
+        - { os: "ubuntu-latest", python-version: "3.13-dev", disable-gil: true }
         # M1 only available for 3.10+
         - os: "macos-13"
           python-version: "3.9"
@@ -70,6 +72,7 @@ jobs:
 
     - name: Set up Python ${{ matrix.python-version }}
       uses: actions/setup-python@v5
+      if: "!endsWith(matrix.python-version, '-dev')"
       with:
         python-version: ${{ matrix.python-version }}
         allow-prereleases: true
@@ -78,6 +81,13 @@ jobs:
           ".ci/*.sh"
           "pyproject.toml"
 
+    - name: Set up Python ${{ matrix.python-version }} (free-threaded)
+      uses: deadsnakes/action@v3.1.0
+      if: endsWith(matrix.python-version, '-dev')
+      with:
+        python-version: ${{ matrix.python-version }}
+        nogil: ${{ matrix.disable-gil }}
+
     - name: Build system information
       run: python3 .github/workflows/system-info.py