Stack was:

looking in bool RegexParser::performMatch
it only sets up processor if hits
if (len >= algo->minPatternLength)
.. block
however len == 2 and algo->minPatternLength == 4, so it doesn't setup state.processor

Then it enters:
if (state.numMatched == 0)
.. block and algo->notMatched = true
and calls createMatchRow

So it's segfaulting on uninitialized or invalid old state.processor by the looks of it.