?
Отладчик такой, например, вот я отладил свой код:
$ gcc -std=c99 -O0 -ggdb test-arr.c -o test-arr
$ gdb ./test-arr
Reading symbols from ./test-arr...done.
(gdb) b main
Breakpoint 1 at 0x6eb: file test-arr.c, line 4.
(gdb) r
Starting program: /home/avs/sandbox/test-arr
Breakpoint 1, main () at test-arr.c:4
4 {
(gdb) n
6 scanf("%d", &N);
(gdb) n
10
7 int arr[N];
(gdb) p N
$1 = 10
(gdb) n
8 return 0;
(gdb) n
9 }
(gdb) n
__libc_start_main (main=0x5555555546da <main>, argc=1, argv=0x7fffffffde28, init=<optimized out>, fini=<optimized out>, rtld_fini=<optimized out>, stack_end=0x7fffffffde18) at ../csu/libc-start.c:344
344 ../csu/libc-start.c: No such file or directory.
(gdb) c
Continuing.
[Inferior 1 (process 16532) exited with code 0]
(gdb)