[yz@localhost src]$ gcc sigwait_demo.c -g -o sigwait_demo
[yz@localhost src]$ gdb sigwait_demo
GNU gdb (GDB) Red Hat Enterprise Linux 7.6.1-110.el7
...
(gdb) b main
Breakpoint 1 at 0x400672: file sigwait_demo.c, line 28.

(gdb) r
Starting program: sigwait_demo 
Breakpoint 1, main (argc=1, argv=0x7fffffffe098) at sigwait_demo.c:28
28        sa.sa_flags = SA_RESTART;

(gdb) set g_enable_breakon_sigint = 1
(gdb) b gdb_breakon_sigint
Breakpoint 2 at 0x40062b: file sigwait_demo.c, line 15.

(gdb) c
Continuing.
^C
Breakpoint 2, gdb_breakon_sigint () at sigwait_demo.c:15
15        printf("A chance to break on SIGINT\n")
(gdb)