I will try removing it and see what I get and let you guys know.

This did cross my mind, but since I invoke setsid() right before the signal handler and since the signal handler works fine before exec(), I determined that setsid shouldn't affect what I am seeing. After exec(), the new process should inherit the same process space as the previous process, and since setsid() didn't prevent SIGINT from being caught in the initial process, I figured it shouldn't affect any subsequent exec()d processes. Am I mistaken here?