Here's a stacktrace on Linux without compiler optimizations:
Program terminated with signal SIGSEGV, Segmentation fault.
#0 0x080f504b in smp_fetch_sc_trackers (args=0x9b86de0, smp=0xbfffdfd4,
kw=0x81317c7 "sc0_trackers", private=0x0) at src/stream.c:3265
3265 smp->data.u.sint = stkctr_entry(stkctr)->ref_cnt;
(gdb) bt
#0 0x080f504b in smp_fetch_sc_trackers (args=0x9b86de0, smp=0xbfffdfd4,
kw=0x81317c7 "sc0_trackers", private=0x0) at src/stream.c:3265
#1 0x080fa9b3 in sample_process (px=0x9b85120, sess=0x9b84cb8,
strm=0x9b84d68, opt=6, expr=0x9b86dc0, p=0xbfffdfd4) at src/sample.c:1060
#2 0x080f8d4b in acl_exec_cond (cond=0x9b86d38, px=0x9b85120,
sess=0x9b84cb8, strm=0x9b84d68, opt=6) at src/acl.c:1145
#3 0x080abf45 in http_req_get_intercept_rule (px=0x9b85120,
rules=0x9b8515c, s=0x9b84d68, deny_status=0xbfffe11c) at
src/proto_http.c:3314
#4 0x080ade7d in http_process_req_common (s=0x9b84d68, req=0x9b84d74,
an_bit=16, px=0x9b85120) at src/proto_http.c:4157
#5 0x080f0d0b in process_stream (t=0x9b84d10) at src/stream.c:1819
#6 0x0805b19c in process_runnable_tasks () at src/task.c:238
#7 0x0804d432 in run_poll_loop () at src/haproxy.c:1692
#8 0x0804e090 in main (argc=3, argv=0xbfffe404) at src/haproxy.c:2059
(gdb) bt full
#0 0x080f504b in smp_fetch_sc_trackers (args=0x9b86de0, smp=0xbfffdfd4,
kw=0x81317c7 "sc0_trackers", private=0x0) at src/stream.c:3265
stkctr = 0x81594b4 <stkctr>
#1 0x080fa9b3 in sample_process (px=0x9b85120, sess=0x9b84cb8,
strm=0x9b84d68, opt=6, expr=0x9b86dc0, p=0xbfffdfd4) at src/sample.c:1060
conv_expr = 0x8159540 <static_pattern>
#2 0x080f8d4b in acl_exec_cond (cond=0x9b86d38, px=0x9b85120,
sess=0x9b84cb8, strm=0x9b84d68, opt=6) at src/acl.c:1145
suite = 0x9b86d78
term = 0x9b86d90
expr = 0x9b86c08
acl = 0x9b86f40
smp = {flags = 4, data = {type = 2, u = {sint = 0, ipv4 =
{s_addr = 0}, ipv6 = {__in6_u = {__u6_addr8 = '\000' <repeats 15 times>,
__u6_addr16 = {
0, 0, 0, 0, 0, 0, 0, 0}, __u6_addr32 = {0, 0, 0,
0}}}, str = {str = 0x0, size = 0, len = 0}, meth = {meth =
HTTP_METH_OPTIONS, str = {
str = 0x0, size = 0, len = 0}}}}, ctx = {p = 0x0, i =
0, ll = 0, d = 0, a = {0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0}}, px =
0x9b85120,
sess = 0x9b84cb8, strm = 0x9b84d68, opt = 6}
acl_res = ACL_TEST_FAIL
suite_res = ACL_TEST_PASS
cond_res = ACL_TEST_FAIL
#3 0x080abf45 in http_req_get_intercept_rule (px=0x9b85120,
rules=0x9b8515c, s=0x9b84d68, deny_status=0xbfffe11c) at
src/proto_http.c:3314
ret = 0
sess = 0x9b84cb8
txn = 0x9b84f40
cli_conn = 0x0
rule = 0x9b86b80
ctx = {line = 0xb76e550f <__memcpy_ssse3+31>
"\201\303\061\317\003", idx = -1073749820, val = 134893733, vlen = 0,
tws = -1073749784,
del = 134895703, prev = 163073640}
auth_realm = 0x0
act_flags = 2
len = 0
#4 0x080ade7d in http_process_req_common (s=0x9b84d68, req=0x9b84d74,
an_bit=16, px=0x9b85120) at src/proto_http.c:4157
sess = 0x9b84cb8
txn = 0x9b84f40
msg = 0x9b84f94
rule = 0x9b84db0
wl = 0x0
verdict = 135013966
deny_status = 2
#5 0x080f0d0b in process_stream (t=0x9b84d10) at src/stream.c:1819
max_loops = 199
ana_list = 48
ana_back = 48
flags = 9469954
srv = 0x0
s = 0x9b84d68
sess = 0x9b84cb8
rqf_last = 8421376
rpf_last = 2147483648
rq_prod_last = 7
rq_cons_last = 0
rp_cons_last = 7
rp_prod_last = 0
req_ana_back = 0
req = 0x9b84d74
res = 0x9b84da8
si_f = 0x9b84eac
si_b = 0x9b84ec4
#6 0x0805b19c in process_runnable_tasks () at src/task.c:238
t = 0x9b84d10
max_processed = 0
#7 0x0804d432 in run_poll_loop () at src/haproxy.c:1692
next = 0
#8 0x0804e090 in main (argc=3, argv=0xbfffe404) at src/haproxy.c:2059
err = 0
retry = 200
limit = {rlim_cur = 4011, rlim_max = 4011}
errmsg = "\000 v\267\264\342\377\277\000 v\267
$v\267p\201\267\tp\201\267\tt\361b\267x\201\267\t\000\000\000\000<\000\000\000\002\000\000\000\b\343\377\277\000
\025\b8\000\000\000 $v\267\030\343\377\277\000e{\267\030\260\021\b\000
\025\b\032\000\000\000\244\201\267\t\030\343\377\277\037\333\017\b\252\201\267\t\222H\023\b"
pidfd = -1
(gdb) quit
