The Perl Debugger
The final concern with using the debugger is compilation. Because the debugger is actually just debugging code inserted into your script, it is necessary that your script be compilable. That is, there should be no syntax errors.
Mastering the Perl 5 debugger is almost as useful as mastering Perl 5 itself. It allows you to take part in the actual execution of your program, to examine and experiment. It allows you to kill the bugs.