use strict;
use warnings;
BEGIN{
    push @ARGV, \'$hash{key}{key}{key} = "value"' if (!@ARGV);
}

our %hash;

my $file_name = $ARGV[0];
Some::Module::some_sub($file_name);
print $hash{key}{key}{key}, "\n";

package Some::Module;
sub some_sub{
    our %hash;
    *hash = *main::hash;
    my $fname = shift;
    open my $fh, '<', $fname or die "cannot open input";
    my $string = <$fh>;
    eval $string;
    my $debug = 'foo';  # Just a place for debug to stop.
}