D:\tmp\pm>perl -d tst_recursion.pl

Loading DB routines from perl5db.pl version 1.57
Editor support available.

Enter h or 'h h' for help, or 'perldoc perldebug' for more help.

main::(tst_recursion.pl:4):     our $limit =1050;

  DB<1> c
main::tst(tst_recursion.pl:9):      $l++;
1000 levels deep in subroutine calls!

  DB<1>