You can't get there from here

`Acme::HaltingProblem`

        use Acme::HaltingProblem;

        my $halts = halts($CODE, $INPUT);
        my $does_halt = $halts ? "does halt" : "does not halt";
        print "<$CODE> $does_halt when given input <$INPUT>.\n";

Well, no
Acme::HaltingProblem doesn't always work
Could we fix it?
It turns out we can't.
Here's why.