DB<3> a 6 print ("\$y $y\n")
  DB<4> n
  DB<4> 
  DB<4> 
$y 3
  DB<4> 
$y 4
  DB<4> 
Use of uninitialized value $y in concatenation (.) or string at (eval 9)[/usr/share/perl/5.18/perl5db.pl:732] line 1.
 at (eval 9)[/usr/share/perl/5.18/perl5db.pl:732] line 1.
	eval 'no strict; ($@, $!, $^E, $,, $/, $\\, $^W) = @DB::saved;package main; print ("\\$y $y\\n");
' called at /usr/share/perl/5.18/perl5db.pl line 732
	DB::eval called at /usr/share/perl/5.18/perl5db.pl line 2661
	DB::DB called at test.pl line 5
$y 
  DB<4>