macOS falls back to 10.9

[nschloe]

I build my wheels with

jobs:
  build_wheels:
    name: Build wheels on ${{ matrix.os }}
    runs-on: ${{ matrix.os }}
    strategy:
      fail-fast: false
      matrix:
        os: [ubuntu-latest, macos-latest, windows-latest]

    steps:
      - uses: actions/checkout@v4

      - name: Build wheels
        uses: pypa/cibuildwheel@v2.16.1
        env:
          CIBW_TEST_REQUIRES: pytest
          CIBW_TEST_COMMAND: "pytest {project}/tests"
          CIBW_ARCHS_MACOS: x86_64 arm64

My pyproject.toml has

[tool.cibuildwheel]
build-verbosity = 1
test-requires = "pytest"
test-command = "pytest {project}/tests"

# Needed for full C++17 support
[tool.cibuildwheel.macos.environment]
MACOSX_DEPLOYMENT_TARGET = "10.14"

Curiously, on macOS it reports

[...]
Building cp38-macosx_x86_64 wheel
CPython 3.8 macOS x86_64

Installing Python cp38...
  
  + pkgutil --pkgs
  + Download https://www.python.org/ftp/python/3.8.10/python-3.8.10-macosx10.9.pkg to
[...]

Apparently it falls back to the ancient macOS 10.9, causing further problems down the line.

Any idea why this might be happening?

[henryiii]

CPython only ships a 10.9 binary. It works for future macOS. What problem are you having?

[henryiii]

Setting CIBW_ENVIRONMENT overrides tool.cibuildwheel.*environment values. So you are losing the value by setting it this way.

Scikit-build-core already passes --strip when installing, do you need to pass -g0?

[henryiii]

We've thought about ways to merge values, but none of them have looked all that nice. The problem is if we merged by default, there'd be no way to delete an environment variable via an override.

[Czaki]

seem to make a difference. When present, the cibuildwheel chooses macosx 10.9. Is this a bug?

It may overwirrite --macosx-version-min flag that is used by part of build system to pass information about deployment target.

[henryiii]

No, it's supported this way, the problem is the environment is set to CFLAGS/CXXFLAGS, and the MACOSX_DEPLOYMENT_TARGET is not present, since the environment variable has overridden the toml file setting.

CIBW_ENVIRONMENT: >
            CFLAGS='-s'
            CXXFLAGS='-s'
            MACOSX_DEPLOYMENT_TARGET='10.14'

Would fix it, for example.

[nschloe]

Setting CIBW_ENVIRONMENT overrides tool.cibuildwheel.*environment values. So you are losing the value by setting it this way.

Aha! I hadn't realized that all other settings are overridden.

Scikit-build-core already passes --strip when installing, do you need to pass -g0?

I absolutely do not want to ship debug symbols, and I'd like to have that explicit somewhere in my own code. That's why I put the flags there.

[henryiii]

It’s the default, but:

[tool.scikit-build]
install.strip = true

would make it explicit.