Using strace and ltrace to help with troubleshooting on Linux
Both strace and ltrace are powerful command-line tools for debugging and troubleshooting programs on Linux: Strace captures and records all system calls made by a process as well as the signals received, while ltrace does the same for library calls.
If a program acts differently than you expect, you can use these tools to see “behind the curtain” and maybe get some clues as to what is going on.
Be forewarned, though. When you use either of these commands, you will end up with a lot of output to look through. Still, that can tell you quite a bit about how a process is working and sometimes give you important insights.