CCPP Framework Meeting Minutes 2025 08 28

Agenda

• GitHub issues/PRs
• New items
• Updates
• Other business
• notes

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Attendees: Michael Kavulich, Cheryl Craig, Dustin Swales, Jordan Powers, RhaeSung Kim, Courtney Peverley, Jesse Nusbaumer, Dom Heinzeller

GitHub issues, PRs, discussions

• Allow different Fortran source directory #675

  • Associated issue: #674
  • Some ongoing discussion

• Allow repeat subcycle variables & nested subcycles of identical length #678

  • Associated issue: #676
  • Some requested changes

• Capgen does not allow for two subcycles that use the same loop standard name Issue#677

• Updates to main

  • Update main from develop 2025/07/24 #668
    • Still one RRTMG test failing bit-for-bit?
  • Bug fixes for ccpp_prebuild to work with partially case-insensitive capgen parser #669
    • Merged

Drafts/On Hold

• DON'T MERGE UNTIL DEVELOP IS UNFROZEN: Skip variable parse checks during fortran parsing #673

New items for discussion

Updates from last time

Previous notes

Other business

Meeting notes

• Updates to main

  • Dustin: Dom figured out the issue with the RRTMGP test
    • RRTMGP requires persistent variable (unclear which)
      • Long-term, needs a host-side RRTMGP fix
      • Short-term, there’s a stop-gap
      • Used to be using wrong data, now using 0s which is also wrong
  • Can merge #668 now (once Dustin approves)
  • Dom to open PR to UFS weather model with stop-gap

• Allow different Fortran source directory (#675)

  • Waiting on Steve to respond to questions/requests
  • Needs further reviews

• Allow repeat subcycle (#678)

  • Waiting on reviews; Steve’s re-review

• Dom: how far are we from transitioning from prebuild to capgen? What’s the strategy/timeline?

  • Do we need a project board? List of issues that still need to be addressed?
  • Dustin: will open a PR with the necessary mods for SCM
    • Including updating build system to use makefiles instead of datatable
    • board - not well maintained
  • How do we do the actual switch?
    • Hard switch? Keep prebuild around while things are being finalized?

• Discussion on Capgen unification: project board https://github.com/orgs/NCAR/projects/110/views/1

  • Created issues for each host model that needs to transition to Capgen (SCM, UFS, NEPTUNE)
    • Transition NEPTUNE to capgen #679
    • Transition CCPP-SCM to Capgen #680
    • Will create/attach subissues for each specific problem that needs to be solved for each host
    • Will have standing topic to discuss this project board every meeting