Architecture dependent / independent packages

[nim65s]

ref. #790

I think a proper fix on our side would be to expose a boolean option for arch independent packages, and install the CMake exports in <prefix>/(lib/<arch>|lib*|share)/cmake/<name>*/ with either CMAKE_INSTALL_LIBDIR or CMAKE_INSTALL_DATAROOTDIR depending on that option.

[ahoarau]

1. What about just using CMAKE_INSTALL_DATAROOTDIR (i.e. <prefix>/share/cmake/<pkg>) and dropping the CMAKE_INSTALL_LIBDIR completely ?
2. If the system has arch-dependant lib layout like <prefix>/lib/<arch>/<pkg>) , can we still install in just <prefix>/lib/<pkg> ?

[nim65s]

This would break multi arch systems

[ahoarau]

Could you elaborate why option 1 wouldn't work ?

[nim65s]

Do you think we can have a single share/cmake/toto/toto-config.cmake that will work for both lib/x86_64-linux-gnu/libtoto.so and lib/aarch64-linux-gnu/libtoto.so ?
Usually, that is why we have both lib/x86_64-linux-gnu/cmake/toto/toto-config.cmake && lib/aarch64-linux-gnu/cmake/toto/toto-config.cmake

[ahoarau]

Sorry I thought you were talking about where to install the actual jrl-cmakemodules cmake files.
Those lines got me confused https://github.com/jrl-umi3218/jrl-cmakemodules/blob/master/CMakeLists.txt#L145-L157

Let's discuss it on visio, I'm not sure to grasp the whole problem.