Segfault in Search by triplet with SMOG configuration

There is seemingly an issue when running Allen in Moore in Search by triplet:

Several hundreds of events run successfully and then Allen just seg faults. Running with the --gdb flag it seems that the error happens in the velo_search_by_triplet::track_forwarding function.

it happens at event 644 of this script: https://gitlab.cern.ch/lhcb/Moore/-/blob/kmattiol_SMOG2/Hlt/Hlt1Conf/options/hlt1_smog_example.py

the seg fault seems to be a happen at line 603 when one of the inputs to the Velo::TrackletHits happens to be zero (https://gitlab.cern.ch/lhcb/Allen/-/blob/master/device/velo/search_by_triplet/src/SearchByTriplet.cu)