set CROSSCOMPILING_EMULATOR

[isuruf]

Checklist

• Used a personal fork of the feedstock to propose changes
• Bumped the build number (if the version is unchanged)
• Reset the build number to 0 (if the version changed)
• Re-rendered with the latest conda-smithy (Use the phrase @conda-forge-admin, please rerender in a comment in this PR for automated rerendering)
• Ensured the license file is being packaged.

[conda-forge-webservices]

Hi! This is the friendly automated conda-forge-linting service.

I just wanted to let you know that I linted all conda-recipes in your PR (recipe) and found it was in an excellent condition.

[hmaarrfk]

Do you really want to support a variable that is sometimes a string, sometimes a boolean?

On the linux code path we have:

 33         if [ -f ${CI_SUPPORT}/${CONFIG}.yaml ]; then                                                                                                                                                       
 34             echo "CMAKE_CROSSCOMPILING_EMULATOR: " >> ${CI_SUPPORT}/${CONFIG}.yaml
 35             echo "- /usr/bin/qemu-${HOST_PLATFORM_ARCH}-static"  >> ${CI_SUPPORT}/${CONFIG}.yaml
 36             echo "CROSSCOMPILING_EMULATOR: " >> ${CI_SUPPORT}/${CONFIG}.yaml    
 37             echo "- /usr/bin/qemu-${HOST_PLATFORM_ARCH}-static"  >> ${CI_SUPPORT}/${CONFIG}.yaml
 38         fi 

[isuruf]

I agree that it's confusing. However, we usually test that it is non-empty on Linux too. CMake use CMAKE_CROSSCOMPILING_EMULATOR to launch binaries, but I'm not setting it here because I couldn't think of what to set here. The emulator is called by the OS itself so there's no path for it.

[hmaarrfk]

Understood on the non-emptiness front. Is the following suggestion possible:
conda-forge/conda-smithy#1808 (comment)

[hmaarrfk]

Good by me, but I haven't tested on windows. merge if you have

[isuruf]

This is tested on CI here.