NAG CAM5 subcolumns test fails since update to match alpha08l externals

[nusbaume]

What happened?

Since #1511

The NAG CAM5 subcolumns test fails the restart comparison. This test works with intel, so we did not fix it for that PR, but it needs to be investigated.

The differences are in the cpl.hi file:

/scratch/cluster/cacraig/aux_cam_nag_20260320202120/ERC_D_Ln9.f10_f10_mt232.FHIST_C5.izumi_nag.cam-outfrq3s_subcol.GC.aux_cam_nag_20260320202120/run/ERC_D_Ln9.f10_f10_mt232.FHIST_C5.izumi_nag.cam-outfrq3s_subcol.GC.aux_cam_nag_20260320202120.cpl.hi.1979-01-01-16200.nc.base.cprnc.out

What are the steps to reproduce the bug?

Run the following commands on Izumi:

git clone https://github.com/ESCOMP/CAM.git
cd CAM
git checkout cam_development
bin/git-fleximod update
cd test/system
env CAM_FC=NAG BL_TESTDIR=<latest baselines> ./test_driver.sh -f

You should then see a baseline restart test failure for test ERC_D_Ln9.f10_f10_mt232.FHIST_C5.izumi_nag.cam-outfrq3s_subcol

What CAM tag were you using?

cam6_4_158

What machine were you running CAM on?

CGD machine (e.g. izumi)

What compiler were you using?

NAG

Path to a case directory, if applicable

/scratch/cluster/cacraig/aux_cam_nag_20260320202120/ERC_D_Ln9.f10_f10_mt232.FHIST_C5.izumi_nag.cam-outfrq3s_subcol.GC.aux_cam_nag_20260320202120/

Will you be addressing this bug yourself?

Any CAM SE can do this

Extra info

No response

[PeterHjortLauritzen]

Due to higher-priority items on the to-do list and uncertainty regarding sub-column support in CAM-SIMA (as of the time of writing), this issue has been placed on the back burner.