Hacktoberfest 2026: the issues maintainers tagged for October, open and beginner-friendly. Browse Hacktoberfest issues

FAIL SMS_D_Ld3_PS.f09_t233.I1850Clm60BgcNoAnthroRtm.derecho_intel.clm-decStart1851_noinitial--clm-matrixcnOn

Open
  • Is something wrong?
#4,263 1 comment 0 reactions 0 assignees View on GitHub

Maintainers usually reply within 1 day

Nobody has claimed this yet.

Assessment

Difficulty
4/5
Estimated time
3-5 days
Newbie friendliness
18/100
Issue type
Bug
Clarity
Mostly clear
Activity status
Active
Tech stack
fortran
Domain
backend, testing

Research direction

The failure is a "floating invalid" trap at line 764 of CNSoilMatrixMod.F90 when the aux_clm test runs with matrixcnOn; the same test passes without that option. Start by reading the soil matrix code around that line and the aux_clm test definition that the author already edited to drop matrixcnOn. Done means either the root cause is identified and fixed, or the test is confirmed to pass with the intended configuration.

Written by the indexing model from the issue text.

Description

bug closed: wontfix priority: low

This issue documents a failure that may affect Paleo users (most likely), when running with matrixcnOn and the compset of this aux_clm test:
SMS_D_Ld3_PS.f09_t233.I1850Clm60BgcNoAnthroRtm.derecho_intel.clm-decStart1851_noinitial--clm-matrixcnOn.

  • The test failed consistently in PR #4234 with "floating invalid" in line 764 CNSoilMatrixMod.F90, not line 793 of the tests that pass by resubmitting a few times
  • The test's predecessor with f09_g17 passed in the baseline (ctsm5.4.063) and again while testing PR #4234
  • In RTM's testlist we use f09_f09_mt233 ONLY (instead of f09_t233), but the test fails also with that
  • In RTM's testlist we never test BgcNoAnthroRtm (so only SpNoAnthroRtm, so we didn't catch the problem in the corresponding RTM PR); that's an omission, though ok since we test BgcNoAnthroRtm in aux_clm
  • Testing RTM with matrixcnOn is unnecessary because we use the latter ONLY in SASU mode (a phase of the BGC accelerated spin-up), during which RTM preferably remains unset to conserve compute cycles
  • The test without matrixcnOn passes, so I updated this aux_clm test by removing matrixcnOn
General bug information

CTSM version you are using: PR #4234 testing against ctsm5.4.063 baseline

Does this bug cause significantly incorrect results in the model's science? No

Configurations affected: f09_t233.I1850Clm60BgcNoAnthroRtm with matrixcnOn

Dominant language
Fortran
Stars
352
Forks
365
Avg merge
2d 14h
Merged PRs (30d)
13

Getting set up

First steps

  1. Read the whole issue, then the project's contributing guide.
  2. Comment on the issue to say you are picking it up — it saves two people doing the same work.
  3. Fork the repository and make your change on a branch.
  4. Open a pull request that references the issue number.

More from ESCOMP/CTSM

All issues in ESCOMP/CTSM

Similar issues

More Backend & API Design issues

Get new issues in your inbox

A short digest of beginner-friendly GitHub issues.