This is probably not what you're talking about, but I know that regexps Perl blocks ((?{ }) and (??{ })) will capture lexicals. I use package variables for those.

sub lexvar {
   my $var = shift;
   /(?{ print($var, "\n") })/;
}

sub pkgvar {
   local our $var = shift;
   /(?{ print($var, "\n") })/;
}

lexvar('abc');  # abc
lexvar('def');  # abc

pkgvar('abc');  # abc
pkgvar('def');  # def
[download]

It's not limited to 5.6, though. 5.6, 5.8 and 5.10 all give the same output.

Don't make us guess, show us some code!