or download this
perl -d:ptkdb my_script.pl
couldn't connect to display ":0" at /usr/lib64/perl5/vendor_perl/5.8.8
+/x86_64-linux-thread-multi/Tk/MainWindow.pm line 55.
MainWindow->new() at Devel/ptkdb.pm line 1147
Can't call method "setup_main_window" on unblessed reference at Devel/
+ptkdb.pm line 4151.