sub Dump {
    no strict 'refs';
    my $implementation = __PACKAGE__->implementation;
    my $debug; # My own debug variable
    for my $option (@dump_options) {
        my $var = "$implementation\::$option";
        $debug = $var if $var =~/UseCode/; #the option I wish to set
        my $value = $$var;
        local $$var; # <-- PROBLEM! Local to "for", not "sub"
        $$var = defined $value ? $value : ${"YAML::$option"};
        # Here I print out the option in each iteration of the loop
        print STDERR "$debug = $$debug\n";
    }
    # And the final value:
    print STDERR "FINAL: $debug = $$debug\n";
    return &{"$implementation\::Dump"}(@_);
}