Add pkg-config

Author: znicholls

.github/workflows/build-wheels.yaml

@@ -86,6 +86,18 @@ jobs:
           echo "CC=clang-cl" | Out-File -FilePath $env:GITHUB_ENV -Encoding utf8 -Append
           echo "CXX=clang-cl" | Out-File -FilePath $env:GITHUB_ENV -Encoding utf8 -Append
           echo "FC=flang-new" | Out-File -FilePath $env:GITHUB_ENV -Encoding utf8 -Append
+      # From numpy: https://github.com/numpy/numpy/blob/37c9cb68ba7db9c48bc0e3354953c57a78d2b0e8/.github/workflows/wheels.yml#L133
+      - name: pkg-config-for-win-arm
+        if: ${{ matrix.os == 'windows-11-arm' }}
+        run: |
+          choco install -y --no-progress --stoponfirstfailure --checksum 6004DF17818F5A6DBF19CB335CC92702 pkgconfiglite
+          $CIBW = "${{ github.workspace }}/.openblas"
+          # pkgconfig needs a complete path, and not just "./openblas since the
+          # build is run in a tmp dir (?)
+          # It seems somewhere in the env passing, `\` is not
+          # passed through, so convert it to '/'
+          $CIBW = $CIBW.replace("\","/")
+          echo "CIBW_ENVIRONMENT_WINDOWS=PKG_CONFIG_PATH=$CIBW" >> $env:GITHUB_ENV
       # - name: Specify MSVC toolchain - windows-arm
       #   if: ${{ matrix.os == 'windows-11-arm' }}
       #   # When building on windows ARM, we need to use the MSVC toolchain