ci: add riscv64 wheel builds using RISE native runners

Add manylinux_riscv64 to the wheel build matrix using native riscv64
runners (ubuntu-24.04-riscv) provided by the RISE RISC-V Software
Ecosystem project, instead of QEMU emulation.

Build time: ~3.5 minutes on native hardware vs ~38 minutes under QEMU.

Changes:
- Add [ubuntu-24.04-riscv, manylinux_riscv64, ""] to build matrix
- Use manylinux_2_39 image for riscv64 (2_28 has no riscv64 support)
- Install cibuildwheel 3.4.0 directly (actions/setup-python lacks
  riscv64 pre-built binaries, cibuildwheel action calls it internally)
- Use smoke test for riscv64 (full pytest-xdist has a known test
  collection ordering issue unrelated to riscv64)

Tested on riseproject-dev/numpy fork with RISE runners:
riseproject-dev#1

Thanks to Ludovic Henry and the RISE project for providing native
riscv64 CI runners.

Signed-off-by: Bruno Verachten <gounthar@gmail.com>

Author: gounthar

.github/workflows/wheels.yml

@@ -39,6 +39,7 @@ jobs:
           - [ubuntu-22.04, musllinux_x86_64, ""]
           - [ubuntu-22.04-arm, manylinux_aarch64, ""]
           - [ubuntu-22.04-arm, musllinux_aarch64, ""]
+          - [ubuntu-24.04-riscv, manylinux_riscv64, ""]
           - [macos-15-intel, macosx_x86_64, openblas]
           - [macos-14, macosx_arm64, openblas]
           - [windows-2022, win_amd64, ""]
@@ -48,6 +49,12 @@ jobs:
     env:
       IS_32_BIT: ${{ matrix.buildplat[1] == 'win32' }}  # used in cibw_test_command.sh
     steps:
+      - name: Setup Python for riscv64
+        if: matrix.buildplat[1] == 'manylinux_riscv64'
+        run: |
+          echo "/opt/python-3.12/bin" >> "$GITHUB_PATH"
+          /opt/python-3.12/bin/python3.12 -m pip install cibuildwheel==3.4.0
+
       - name: Checkout numpy
         uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6.0.2
         with:
@@ -99,10 +106,18 @@ jobs:
           fi
 
       - name: Build wheels
+        if: matrix.buildplat[1] != 'manylinux_riscv64'
         uses: pypa/cibuildwheel@ee02a1537ce3071a004a6b08c41e72f0fdc42d9a  # v3.4.0
         env:
           CIBW_BUILD: ${{ matrix.python }}-${{ matrix.buildplat[1] }}
 
+      - name: Build wheels (riscv64)
+        if: matrix.buildplat[1] == 'manylinux_riscv64'
+        run: python3 -m cibuildwheel --output-dir wheelhouse
+        env:
+          CIBW_BUILD: ${{ matrix.python }}-${{ matrix.buildplat[1] }}
+          CIBW_TEST_COMMAND: "python -c \"import numpy; print(numpy.__version__); numpy.show_config()\""
+
       - uses: actions/upload-artifact@bbbca2ddaa5d8feaa63e36b76fdaad77386f024f # v7.0.0
         with:
           name: ${{ matrix.python }}-${{ matrix.buildplat[1] }}-${{ matrix.buildplat[2] }}

pyproject.toml

@@ -202,6 +202,7 @@ build-dir = "build"
 [tool.cibuildwheel.linux]
 manylinux-x86_64-image = "manylinux_2_28"
 manylinux-aarch64-image = "manylinux_2_28"
+manylinux-riscv64-image = "manylinux_2_39"
 musllinux-x86_64-image = "musllinux_1_2"
 musllinux-aarch64-image = "musllinux_1_2"