Get cmake --build --target install working

[cwpearson]

• Install the header files and CMake configuration files.
• Add a CI check that builds unit tests and perf tests against the install
• Treat unit_tests and perf_tests as separate CMake projects to facilitate install testing.
• There are probably many problems with this that I don't know enough about CMake to foresee

original below

• Install the header files and CMake configuration files.
• Add a CI check that builds unit tests and perf tests against the install
• Add a CMake configuration -DKokkosComm_INSTALL_TESTING=ON that uses find_package to find KokkosComm and then builds unit tests and perf tests against that
• There are probably many problems with this that I don't know enough about CMake to foresee

[cedricchevalier19]

It's a great idea, but it can be implemented in a simpler manner I think.

You can make the tests an independent project that contains a

if (NOT TARGET KokkosComm::KokkosComm)
  find_package(KokkosComm REQUIRED)
endif()

This way, we do not need special option and we keep the main CMakeLists.txt clean.

[cedricchevalier19]

I am a little skeptical about using mpicxx as a compiler.
MPI does not require it and it can make things strange mixing with gpu compilers.

However, this change can be done in a separate PR if you prefer to ensure all part of the repository are updated.

[cwpearson]

I am a little skeptical about using mpicxx as a compiler. MPI does not require it and it can make things strange mixing with gpu compilers.

However, this change can be done in a separate PR if you prefer to ensure all part of the repository are updated.

I agree, let's tackle this in another PR. I created an issue: https://github.com/cwpearson/kokkos-comm/issues/17