Cross compile the same library

I’m trying to cross compile my libs with the objective to create a package (just a zip) with with the same lib but in different cpu arch.
So I want to compile the same target but with a diff compiler to target a diff arch.
I find it hard to believe that cmake doesn’t support it yet.

You can do this, but you have to build each arch separately, one-at-a-time. CMake only allows you to use one compiler and target platform at a time per build tree.