JULES segmentation fault after spinup

Hi all,

Since I’ve migrated my several of my suites (for running JULES) over to Cylc 8, I can’t seem to get them to run beyond the spinup period. I’ve got three different suites (de001, dg594 and dp235 - (run1)) which admittedly run very similar processes (compile JULES with FCM and then run JULES), but with different ancillary data and grid extent. All fail after the spinup. For all of them, the last line of the job.out shows an output message from JULES which indicates that it has got to the end of the spinup. E.g., for de001, I get this at the end of the file:

[INFO] next_time: Timestep: 87624; Started at: 1999-12-30 23:00:00
[INFO] next_time: Spinup cycle: 1

So it seems that it has reached the end of spinup. The job.err file just has this in it:

[WARN] file:ancillaries.nml: skip missing optional source: namelist:jules_top
[WARN] file:ancillaries.nml: skip missing optional source: namelist:jules_crop_props
[WARN] file:ancillaries.nml: skip missing optional source: namelist:jules_rivers_props
[WARN] file:ancillaries.nml: skip missing optional source: namelist:jules_overbank_props
[WARN] file:ancillaries.nml: skip missing optional source: namelist:urban_properties
[WARN] file:crop_params.nml: skip missing optional source: namelist:jules_cropparm
[WARN] file:imogen.nml: skip missing optional source: namelist:imogen_run_list
[WARN] file:imogen.nml: skip missing optional source: namelist:imogen_anlg_vals_list
[WARN] file:jules_rivers.nml: skip missing optional source: namelist:jules_overbank
[WARN] file:pft_params.nml: skip missing optional source: namelist:jules_pftparm_cable
[WARN] file:prescribed_data.nml: skip missing optional source: namelist:jules_prescribed_dataset(:slight_smile:
[WARN] file:urban.nml: skip missing optional source: namelist:jules_urban_switches
[WARN] file:urban.nml: skip missing optional source: namelist:jules_urban2t_param
[WARNING] INIT_DRIVE: No diffuse shortwave radiation as diff_frac_const = 0.0
[WARNING] init_ic: Provided variable ‘snow_grnd’ is not required, so will be ignored
[WARNING] init_ic: There are no soil points - any land points are land ice
forrtl: severe (174): SIGSEGV, segmentation fault occurred
Image PC Routine Line Source
libc.so.6 00007F60F023E730 Unknown Unknown Unknown
jules.exe 0000000000633821 spinup_check 288 spinup_mod.F90
jules.exe 000000000049F237 next_time 112 next_time.F90
jules.exe 000000000040DFA4 jules 193 jules.F90
jules.exe 000000000040DE3D Unknown Unknown Unknown
libc.so.6 00007F60F02295D0 Unknown Unknown Unknown
libc.so.6 00007F60F0229680 __libc_start_main Unknown Unknown
jules.exe 000000000040DD55 Unknown Unknown Unknown
[FAIL] rose-jules-run # return-code=174
2025-06-13T08:51:38Z CRITICAL - failed/EXIT

I’m not sure what’s going on. This used to run when using cylc7 on the old cylc jasmin node, but now fails. I tried looking at the ancillary data based on this previous query, but it looks fine to me: Segmentation fault (174), JULES on JASMIN

Any ideas?

Many thanks

Jon

SOLVED - there was an issue with my JULES namelist file. I have no idea why this used to work on the old cylc7 setup?