I don't have any PCRE dev stuff unstalled on that particular machine, but to be safe, I went ahead and ran cmake with the -DFORCE_BUNDLED_COPIES=1 flag, but unfortunately, once built... the Sigil binary seg-faulted when trying to run. Not sure what was up there. But anyway... compile time messages indicate no local pcre packages were found and it is indeed using the bundled copy.
Anyway... long story short... the SUPPORT_UCP option
does need to be enabled for unicode property support to work--including the (*UCP), \p{..}, and \X stuff.
I hope you consider enabling that by default going forward, but at least I learned how to configure it myself if necessary. Thanks for that.
