strace - 6.8-2 main

strace is a system call tracer, i.e. a debugging tool which prints out
a trace of all the system calls made by another process/program.
The program to be traced need not be recompiled for this, so you can
use it on binaries for which you don't have source.
.
System calls and signals are events that happen at the user/kernel
interface. A close examination of this boundary is very useful for bug
isolation, sanity checking and attempting to capture race conditions.