exit status 139 on shift-n, and some questions.

using latest nextvi from the github repo. default setup, minor changes in ex.c. linux operating system. 1. possible bug, occasionally, on reverse search the text file exits and returns "running shell: exit status 139". interactive shell is disabled in my ex.c if that has anything to do with it. worth mentioning that im entering text file through file manager called list files (lf). 2. im hitting tab while in command mode by accident and its switching to a new text file (buffer?) and going back to previous buffer is not really intuitive, any way i can change/disable that? 3. i was using openbsd-vi and had commands like: map! ^D ^M^[:.!date +\%b\ \%d\,\ \%Y\ -\ \%A^MkJA in vi.exrc, can i enable that in nextvi? i noticed there's an "export EXINIT=..." mechanism. although that's only performed at startup from what i understand. thanks in advance. edit: also getting segfault message on shift-n, trying version 4.1.