Not sure whether I understood your comment, but for me, strace has been an extremely useful tool for debugging code that I didn't write. Even in the case where

Not sure whether I understood your comment, but for me, strace has been an extremely useful tool for debugging code that I didn't write. Even in the case where source is available, it's often virtually impenetrable, and many times, seeing that a program is attempting a series of system calls that is foolish or guaranteed to fail can quickly provide insight into the problem.