[feature] Add multiarch(any?) arch option to settings.yml

[bog-dan-ro]

This feature is very useful (mostly?) for Android as it supports multiple ABIs in the same apk/aab.

Starting with Qt 5.14.0, Qt for Android provides a way to build the apps for all Android ABIs in one go, and without a multiarch/Any/None in arch settings it's impossible to create an Android multilib Qt package for conan.

[bog-dan-ro]

An even better option is to allow multiple archs: e.g.

#~/.conan/profiles/android_any

# ...
[settings]
arch=[x86, x86_64, armv7, armv8]

[Minimonium]

@a4z is also experiencing the need for this feature but for the iOS toolchain.

The current workaround is to introduce custom multi-arch settings, but it's a very inflexible solution.

[a4z]

yes, this is needed for mobile development, for both iOS, and also for Android (which I will do after all iOS packages are done) . So my need is not limited to just iOS ;-)

[dmn-star]

This will be a very helpful extension. Together with universal libs conan-io/conan-extensions#59

[a4z]

just some notes, while this will work for CMake more or less out of the box,
just add a toolchain file, and or a cmake wrapper.

everything that is not cmake and has no xcode build that can be configured would need to

• have the packages with the wanted architectures as dependencies
• install, probably build those packages
• maybe import the libraries from those packages
• run lipo on the packages for the libraries of the wanted arch, and have a new one

those packages == the same package name/version , just in a the wanted arch , armv7 armv7s arm64

so this seems to be some how a problem

so I understand why the multiarch flag could be a huge problem, some builds would not support them, or , they would become pretty complex

but it would be nice if I could , for example

• have a package curl_fat
• that requires curl armv7, curl armv7s, curl arm64
• installs the packages and lipo the fat binary

and I think this could be possible already today, by using settings via the settings.yml that I give a specific meaning. But this I would have need to test

[dmn-star]

Yes, have android/iOS prebuilt packages from CCI would be great.

conan-io/conan-center-index#537

[memsharded]

Multi-arch support was added back then in Conan 2.2 in #15775, see docs in https://docs.conan.io/2/reference/tools/cmake/cmaketoolchain.html#support-for-universal-binaries-in-macos

It will be limited to iOS, no idea how to get CMake to do multi-archs builds too.

So I suggest:

• Lets close this issue, at the light of the new feature, addressing iOS and proposing a syntax that could be valid for Android too.
• For Android users interested in this, we would need your feedback to know how CMake can be instructed to do multi-archs builds, what needs to be adapted in CMakeToolchain. Please create a new ticket for it, and we can take it from there specifically for Android

Thanks for your feedback!