no eval

gistfile1.pl

package My::Thing;
use strict;

BEGIN {
    $INC{'My/Thing.pm'} = __FILE__;
}

sub import {
    my $class  = shift;
    my $caller = caller;
   
    my $string = "Foo";
   
    my $sym = "$caller\::bar";
    no strict 'refs';
    *$sym = \$string;
}

package consumer;
use strict;

use My::Thing;

print("Bar: $bar\n");

$bar = "This is sparta!";

print("Bar: $bar\n");

1;