Disabling display 3 to avoid infinite recursion.
3: puri.o = There is no member named o.
(gdb) display puri.host.len
4: puri.host.len = 13
(gdb) display realm_prefix.len
5: realm_prefix.len = 0
(gdb) step
102                     realm_prefix.s = cfg_get(registrar, registrar_cfg, realm_pref).s;
5: realm_prefix.len = 0
4: puri.host.len = 13
2: realm_prefix.len = 0
1: realm_prefix = <value optimized out>
(gdb) step
105                     (memcmp(realm_prefix.s, puri.host.s, realm_prefix.len)==0) ) {
5: realm_prefix.len = 0
4: puri.host.len = 13
2: realm_prefix.len = 0
1: realm_prefix = <value optimized out>
(gdb) step
102                     realm_prefix.s = cfg_get(registrar, registrar_cfg, realm_pref).s;
5: realm_prefix.len = 0
4: puri.host.len = 13
2: realm_prefix.len = 0
1: realm_prefix = <value optimized out>
(gdb) step
103                     realm_prefix.len = cfg_get(registrar, registrar_cfg, realm_pref).len;
5: realm_prefix.len = 0
4: puri.host.len = 13
2: realm_prefix.len = 0
1: realm_prefix = <value optimized out>
(gdb) step
104                     if (realm_prefix.len && realm_prefix.len<puri.host.len &&
5: realm_prefix.len = 0
4: puri.host.len = 13
2: realm_prefix.len = 0
1: realm_prefix = {s = 0x0, len = 0}
(gdb) step

Program received signal SIGSEGV, Segmentation fault.
0xffffffff7b312470 in extract_aor (_uri=<value optimized out>, _a=0xffffffff7fffdb70) at common.c:104
104                     if (realm_prefix.len && realm_prefix.len<puri.host.len &&
5: realm_prefix.len = 0
4: puri.host.len = 13
2: realm_prefix.len = 0
1: realm_prefix = {s = 0x0, len = 0}