Omega build issues when supporting E3SM coupling

[grnydawn]

This issue is for collecting Omega build issues and their fixes while supporting E3SM coupling. The list of issues may continue to grow until E3SM coupling is finalized.

Issue 1: The G-case builds successfully, but the B-case build fails.
Fix 1: spdlog and yaml-cpp are now specified with their namespaces:

• spdlog → spdlog::spdlog
• yaml-cpp → yaml-cpp::yaml-cpp
  See commit c6f68da625061b9d451df10f94900e44afc2d6de in the branch:
  https://github.com/E3SM-Project/Omega/tree/andrewdnolan/omega/g-case-coupling

Status: The fix is being verified.

Issue 2: Need to set OMEGA_ARCH when building as part of E3SM (#508)
Status: Under development.

Issue 3: Use driver-owned PIO settings for coupled Omega initialization (#510)
Status: Under development.

Note: The above two issues were created separately before this issue and will continue to be tracked in their respective issues.

Issue 4: B-cases and G-cases build against different versions of spdlog and yaml-cpp.

• B-cases use these libraries from EKAT builds, while G-cases use the versions from Omega's own builds.

Status: The issue is identified.

Issue 5: gswteos-10 has a latent parallel-build race.

• In omega/external/CMakeLists.txt, gswteos is built using ExternalProject_Add, while gswteos-10 is added using add_library.

Status: The issue is identified.