mimas $ dbx -f screen time_1486076555-pid_7960-fid_screen-4.5.0.per-process-core Reading screen core file header read successfully Reading ld.so.1 Reading libcurses.so.2 Reading libelf.so.1 Reading libcrypt_d.so.1 Reading libc.so.1 Reading libgen.so.1 Reading libc_psr.so.1 program terminated by signal ABRT (Abort) 0xffffffff7e8dcbe0: __lwp_kill+0x0008: bcc,a,pt %icc,__lwp_kill+0x18 ! 0xffffffff7e8dcbf0 Current function is CoreDump 1687 abort(); (dbx) where [1] __lwp_kill(0x0, 0x6, 0x0, 0x0, 0x0, 0x0), at 0xffffffff7e8dcbe0 [2] raise(0x6, 0x0, 0xffffffff7e8bb4ec, 0xffffffffffffffff, 0xffffffff7ea3e000, 0x0), at 0xffffffff7e87442c [3] abort(0x1, 0x1d8, 0x100036768, 0x1f1efc, 0x0, 0x0), at 0xffffffff7e84c210 =>[4] CoreDump(sigsig = 11), line 1687 in "screen.c" [5] __sighndlr(0xb, 0x0, 0xffffffff7fffbaf0, 0x10000f450, 0x0, 0xa), at 0xffffffff7e8d8c90 ---- called from signal handler with signal 11 (SIGSEGV) ------ [6] tgetent(0x0, 0x1001d330c, 0x116078, 0x0, 0xffffffff7f028000, 0xffffffff7f030528), at 0xffffffff7ef11fa4 [7] e_tgetent(bp = 0xffffffff7fffc054 "", name = 0x1001d330c "vt100"), line 1341 in "termcap.c" [8] InitTermcap(wi = 0, he = 0), line 121 in "termcap.c" [9] main(ac = 0, av = 0xffffffff7ffff6d8), line 1380 in "screen.c" (dbx) (dbx) quit Actually trying to single step around gets me no where fast : mimas $ dbx ./screen Reading screen Reading ld.so.1 Reading libcurses.so.2 Reading libelf.so.1 Reading libcrypt_d.so.1 Reading libc.so.1 Reading libgen.so.1 (dbx) stop at screen.c:1380 (2) stop at "screen.c":1380 (dbx) run -a -s /usr/xpg4/bin/sh -T vt100 -h 4096 Running: screen -a -s /usr/xpg4/bin/sh -T vt100 -h 4096 (process id 8025) Reading libc_psr.so.1 [screen caught signal 11. (core dumped)] signal HUP (Hangup) in __systemcall6 at 0xffffffff7e8dd3d8 0xffffffff7e8dd3d8: __systemcall6+0x0024: bcs,pn %icc,__systemcall6+0x3c ! 0xffffffff7e8dd3f0 Current function is main 1245 MasterPid = fork(); (dbx) So not very helpful.