New comment by ahesford on void-packages repository

https://github.com/void-linux/void-packages/pull/20218#issuecomment-601360449

Comment:
> Some cross compilation fail. Approach to [use cmake build-style](https://github.com/void-linux/void-packages/pull/18873#issuecomment-597118155) shown by @yopito and @gspe have better chance to work, because this build step is more complex.

There is no clean way around this. The problem is that the cmake modules invoke the Python interpreter to determine the size of a pointer on the target platform and compare it to the size of the pointer expected by the C++ compiler. The C++ (cross-) compiler returns a 4-byte pointer as expected. The Python interpreter is always native, and returns an 8-byte pointer. The test fails. We can never invoke the Python interpreter for the target arch because its binaries are not compatible with the host architecture.

The only useful thing the cmake build step does is prepare some configuration modules for cmake. I've just copied the relevant modules into `files/` and install them where they need to go in `post_install`. The modules do not appear to be architecture dependent and should be usable on all architectures supported by Void.