Create Devel/foo.pm in @INC path with content:

package Devel::foo;
*DB::DB = sub {} if 0;
1;

and run

# perl -d:foo -e '1'
Neoprávněný přístup do paměti (SIGSEGV)

This has been reported to upstream as RT #114990 and fixed in commit:

commit 432d4561c48cd74f3299eddc270a890908a4512e
Author: Jesse Luehrs <doy>
Date:   Mon Sep 24 00:29:06 2012 -0500

    don't crash with -d if DB::DB is seen but not defined [perl #114990]

Only perl-5.16 (F≥18) is affected.