$ perl5.10.0 -we'{ my $x; sub foo { eval q!print $x! } foo }'
Use of uninitialized value $x in print at (eval 1) line 1.
$ perl5.10.0 -we'{ my $x; sub foo { eval q!print $x! } } foo'
Variable "$x" is not available at (eval 1) line 2.
Use of uninitialized value $x in print at (eval 1) line 1.