Well it crashes in fact in check_sockerror() function, when 
it call FD_SET((TSOC) s,&fds)

As it's a local socket s = -500000.

sequence leading to the seg fault:
Back_wait() -> may_deletehttp() -> check_sockerror(-
500000) -> FD_SET(-500000, &fds)

Do I have a too old library anywhere or anything like that?I'm working under
Linux, redhat 8.

thank you
GuiOm