ci: Use cibuildwheel to build wheels (#309)

* pandoc_download: Improve error for unsupported architecture

Show which arch was detected in the error message

* ci: Use cibuildwheel to build binary wheels

 - pypandoc-1.9.tar.gz
   Same as earlier, uses setup.py command to create file
 - pypandoc-1.9-py3-none-any.whl
   Same as earlier, uses setup.py command to create file
 - pypandoc_binary-1.9-py3-none-win32.whl
   Identical to earlier file - generated using cibuildwheel now. I don't have a win32 machine and so unable to test it. But it is identical to the older wheel for win32
 - pypandoc_binary-1.9-py3-none-win_amd64.whl
   New file - similar to win32. Tetsted with my local windows - works fine.
 - pypandoc_binary-1.9-py3-none-macosx_10_15_x86_64.whl
   Not generated anymore (see next line)
 - pypandoc_binary-1.9-py3-none-macosx_10_9_x86_64.whl
   New file - similar to 10_15 but now supports older MacOS versions ^_^/ I don't have a max and so unable to test it. But identical to the older wheel for macos
 - pypandoc_binary-1.9-py3-none-manylinux_2_5_x86_64.manylinux1_x86_64.manylinux_2_17_x86_64.manylinux2014_x86_64.whl
   New file. Tested with my local ubuntu 18.04 works fine and can support older linux versions also
 - pypandoc_binary-1.9-py3-none-musllinux_1_1_x86_64.whl
   New file - I haven't been able to test this yet

.github/workflows/ci.yaml

@@ -48,44 +48,61 @@ jobs:
       - name: run tests
         run: poetry run python tests.py
 
-  builder:
+  builder_pypandoc:
     needs: [test]
     if: github.ref == 'refs/heads/master'
-    strategy:
-      matrix:
-        os: [macos-11, windows-2019]
-    runs-on: ${{ matrix.os }}
+    runs-on: ubuntu-20.04  # Any OS is fine as this wheel is not OS dependent
     steps:
       - name: Check out repository
-        uses: actions/checkout@v2
-      - name: Discover python architecture
-        run: |
-          if [ "$RUNNER_OS" == "Windows" ]; then
-            echo "PYTHON_ARCHITECTURE=x86" >> $GITHUB_ENV
-          else
-            echo "PYTHON_ARCHITECTURE=x64" >> $GITHUB_ENV
-          fi
+        uses: actions/checkout@v3
       - name: Set up python
+        id: setup-python
         uses: actions/setup-python@v4
         with:
-          python-version: "3.9.x"
-          architecture: "${{ env.PYTHON_ARCHITECTURE }}"
-      - name: Print Python Information
-        run: python -VV
+          python-version: 3.9  # Build any 1 python version as this wheel is not version dependent
       - name: Update dependencies
-        run: python -m pip install -U pip wheel setuptools twine
-      - name: Build universal source Archive and wheel
+        run: python -m pip install -U pip wheel setuptools
+      - name: Build wheel
         run: python setup.py sdist bdist_wheel
-      - name: Build binary Archive
-        run: python setup_binary.py download_pandoc bdist_wheel
       - name: Upload artifacts
         uses: actions/upload-artifact@v3
         with:
           name: python-package-distributions
           path: dist/
 
+  builder_pypandoc_binary:
+    needs: [test]
+    if: github.ref == 'refs/heads/master'
+    strategy:
+      matrix:
+        # Ref: https://cibuildwheel.readthedocs.io/en/stable/options/#archs
+        # macos-11     - Creates macosx_x86_64
+        # windows-2019 - Creates {win_amd64,win32}
+        # ubuntu-20.04 - Creates {manylinux,musllinux}_{x86_64,i686}
+        #                In CIBW_SKIP we skip 32bit linux
+        os: [macos-11, windows-2019, ubuntu-20.04]
+    runs-on: ${{ matrix.os }}
+    steps:
+      - name: Check out repository
+        uses: actions/checkout@v3
+      - name: Remove pyproject and use setuptools
+        run: rm pyproject.toml
+      - name: Build binary Archive
+        uses: pypa/[email protected]
+        env:
+          CIBW_BEFORE_ALL: "mv setup_binary.py setup.py && python3 setup.py download_pandoc"
+          CIBW_BUILD: cp39-*  # Build any 1 python version as this wheel is not version dependent
+          # We skip some variants because:
+          # - pandoc does not publish binaries for Linux 32bit
+          CIBW_SKIP: "*-{manylinux_i686,musllinux_i686}"
+      - name: Upload artifacts
+        uses: actions/upload-artifact@v3
+        with:
+          name: python-package-distributions
+          path: wheelhouse/
+
   publisher_release:
-    needs: [builder]
+    needs: [builder_pypandoc, builder_pypandoc_binary]
     if: startsWith(github.event.ref, 'refs/tags/v') && github.ref == 'refs/heads/master'
     runs-on: ubuntu-latest
     steps:
@@ -104,7 +121,7 @@ jobs:
           password: ${{ secrets.PYPI_API_TOKEN }}
 
   publisher_latest:
-    needs: [builder]
+    needs: [builder_pypandoc, builder_pypandoc_binary]
     if: github.ref == 'refs/heads/master'
     runs-on: ubuntu-latest
     steps:

pypandoc/pandoc_download.py

@@ -231,8 +231,9 @@ def download_pandoc(url:Union[str, None]=None,
         # compatibility with py3
         if pf.startswith("linux"):
             pf = "linux"
-            if platform.architecture()[0] != "64bit":
-                raise RuntimeError("Linux pandoc is only compiled for 64bit.")
+            arch = platform.architecture()[0]
+            if arch != "64bit":
+                raise RuntimeError(f"Linux pandoc is only compiled for 64bit. Got arch={arch}.")
 
         # get pandoc_urls
         pandoc_urls, _ = _get_pandoc_urls(version)