Re: pkg/59009: pbulk-build SIGSEGV on null pointer dereference

[Taylor R Campbell <riastradh%NetBSD.org@localhost>]

Hit this again today.

Program terminated with signal SIGSEGV, Segmentation fault.
#0  0x000000007720389c in send_build_info (arg=0x7ada366f7400) at master.c:128
128     master.c: No such file or directory.
(gdb) bt
#0  0x000000007720389c in send_build_info (arg=0x7ada366f7400) at master.c:128
#1  0x0000000077204b57 in deferred_write_handler (fd=<optimized out>, 
    arg=0x7ada2b083060) at event.c:134
#2  0x0000000077204e77 in event_dispatch () at event.c:360
#3  0x0000000077203ef5 in master_mode (
    master_port=0x7f7fff474522 "127.0.0.1:2002", 
    start_script=0x7f7fff4744ec "/pbulk/2026Q2/pkg/libexec/pbulk/build-client-start") at master.c:322
#4  0x0000000077202327 in main (argc=3, argv=0x7f7fff473f58) at pbuild.c:164
(gdb) info locals
peer = 0x7ada366f7400
(gdb) print *peer
$1 = {peer_link = {le_next = 0x0, le_prev = 0x7740f320 <unassigned_peers>},
  job = 0x0, fd = 9, tmp_buf = "G\000\021&", buf = 0x0}
(gdb) print active_peers
 $2 = {lh_first = 0x7ada366f7400}
(gdb) print *active_peers->lh_first
$3 = {peer_link = {le_next = 0x0, le_prev = 0x7740f320 <unassigned_peers>},
  job = 0x0, fd = 9, tmp_buf = "G\000\021&", buf = 0x0}
(gdb) print inactive_peers
$4 = {lh_first = 0x0}
(gdb) print clients_started
$5 = 1
(gdb) print child_event
$6 = {sig_link = {le_next = 0x0, le_prev = 0x7740f3c8 <all_signals>},
  sig_id = 20, sig_received = 0, sig_handler = 0x77203be1 <child_handler>}
(gdb) print child_pid
$7 = 28726

So in this case, it looks like