{
    package a;
    our $foo = 1;
}
{
    package b;
    my $otherpkg = "a";
    my $varname = "$otherpkg\::foo";

    print ${ $varname }, "\n";
    
    # can be simplified as:
    print $$varname, "\n";

    # or the temp variable can be avoided:
    print ${ "$otherpkg\::foo" }, "\n";
}