use v5.12;
use warnings;
say $];

my $t = 42;

sub foo { say eval $_[0] }

foo('$t');

-UUU:----F1  t_dyna_scope.pl   All L4     (Perl) ----
-*- mode: compilation; default-directory: "~/perl/" \
-*-
Compilation started at Thu Aug 29 18:00:33

perl t_dyna_scope.pl
5.036000
42

Compilation finished at Thu Aug 29 18:00:33