unicon.F90 and ifx compiler

[jedwards4b]

What is the feature/what would you like to discuss?

When using
ifx --version
ifx (IFORT) 2023.0.0 20221201

on derecho I am getting an ICE when compiling file
unicos.F90:

ifx: error #10106: Fatal error in /glade/u/apps/common/23.04/spack/opt/spack/intel-oneapi-compilers/2023.0.0/compiler/2023.0.0/linux/bin-ll\
vm/xfortcom, terminated by kill signal                                                                                                      
compilation aborted for /glade/work/jedwards/sandboxes/cesm2_x_alpha/components/cam/src/physics/cam/unicon.F90 (code 1)                     
gmake: *** [/glade/derecho/scratch/jedwards/ERS_Ln9.ne30pg3_ne30pg3_mg17.FLTHIST_v0d.derecho_intel-oneapi.cam-outfrq9s.20230711_134311_zqoz\
2e/Tools/Makefile:975: unicon.o] Error 1        

I have worked around this by removing file unicon.F90 from the SrcFiles file in bld/atm/obj. Do we need to continue to carry this file that we do not use?

Is there anyone in particular you want to be part of this conversation?

No response

Will this change (regression test) answers?

Yes

Will you be implementing this enhancement yourself?

Yes

[cacraigucar]

UNICON is still a supported option for CAM. We still regression test it (though that test is on izumi using the gnu compiler).

@JulioTBacmeister @adamrher @PeterHjortLauritzen @nusbaume - Do any of you have thoughts on this?

[adamrher]

there's if statements for unicon scattered all over the physics and so removing unicon properly would take some work; likely more work than it would take to just fix the issue in this thread.

[jedwards4b]

I have isolated this error in /glade/work/jedwards/ifx_unicon
and will report to intel.

[jedwards4b]

So it turns out that this is failing due to user memory limiting tools on derecho login nodes. If I compile with
qcmd -- ./case.build
it works correctly. I am going to remove the change from ccs_config - we will need to remind users to use the qcmd option when building cesm on derecho.

[cacraigucar]

@jedwards4b - is this issue safe to close now?

[jedwards4b]

Yes, I think so. We need to communicate that compiling cesm on the login nodes of derecho is problematic and should not be done.