Intel to AppleSilicon#
On macOS, AppleClang has excellent support for making Apple Silicon and
Universal2 binaries (both architectures in one binary). Scikit-build-core
CMAKE_SYSTEM_PROCESSOR is not in the cmake args. These
values are set by cibuildwheel when cross-compiling.
If you link to any binaries, they need to be Universal2, so that you get the Apple Silicon component. This means you cannot use homebrew binaries (which are always native, and not designed to be used for building portable binaries anyway). Header-only dependencies, including NumPy, do not need to be Universal2.
Intel to ARM#
Scikit-build-core respects setuptools-style
DIST_EXTRA_CONFIG. If is set to a
file, then scikit-build-core reads the
build_ext.library_dirs paths to find
the library to link to. You will also need to set
SETUPTOOLS_EXT_SUFFIX to the
correct suffix. These values are set by cibuildwheel when cross-compiling.
It should be possible to cross-compile to Linux, but due to the challenges of
getting the manylinux RHEL devtoolkit compilers, this is currently a TODO. See
for an alternative package’s usage of toolchain files.
Intel to Emscripten (Pyodide)#
When using pyodide-build, Python is set up to report the cross-compiling values
_PYTHON_SYSCONFIGDATA_NAME. This causes values like
EXT_SUFFIX to be reported by
sysconfig as the cross-compiling values.
This is unfortunately incorrectly stripped from the cmake wrapper pyodide uses, so FindPython will report the wrong values, but pyodide-build will rename the .so’s afterwards.