mergeArms fails when processing SuNSS data

When running mergeArms.py

mergeArms.py /projects/HSC/PFS/Subaru --calib /projects/HSC/PFS/Subaru/CALIB-PFI-20211220 --rerun=hassans/sunss/2022jan_apcorrb_mergeArms_2022-02-04_11-18-01 -j10 --doraise --id visit=71280^71281[...] arm=b^r

(full list of visits truncated for brevity)

The following error is raised:

File "/tigress/HSC/PFS/stack/20190925/stack/miniconda3-4.5.12-1172c30/Linux64/drp_stella/w.2022.04/python/pfs/drp/stella/mergeArms.py", line 196, in runDataRef
results = self.run(spectra, pfsConfig, lsfList)
File "/tigress/HSC/PFS/stack/20190925/stack/miniconda3-4.5.12-1172c30/Linux64/drp_stella/w.2022.04/python/pfs/drp/stella/mergeArms.py", line 153, in run
lsfList = [self.mergeLsfs(ll, ss) for ll, ss in zip(lsfList, spectra)]
File "/tigress/HSC/PFS/stack/20190925/stack/miniconda3-4.5.12-1172c30/Linux64/drp_stella/w.2022.04/python/pfs/drp/stella/mergeArms.py", line 153, in <listcomp>
lsfList = [self.mergeLsfs(ll, ss) for ll, ss in zip(lsfList, spectra)]
File "/tigress/HSC/PFS/stack/20190925/stack/miniconda3-4.5.12-1172c30/Linux64/drp_stella/w.2022.04/python/pfs/drp/stella/mergeArms.py", line 415, in mergeLsfs
return

Unknown macro: {ff}

File "/tigress/HSC/PFS/stack/20190925/stack/miniconda3-4.5.12-1172c30/Linux64/drp_stella/w.2022.04/python/pfs/drp/stella/mergeArms.py", line 415, in <dictcomp>
return

Unknown macro: {ff}

File "/tigress/HSC/PFS/stack/20190925/stack/miniconda3-4.5.12-1172c30/Linux64/drp_stella/w.2022.04/python/pfs/drp/stella/mergeArms.py", line 415, in <listcomp>
return

Unknown macro: {ff}

KeyError: 2