Sorry, I don't think I was very clear in that explanation; I can see you've added the return, but it'll still have the same problem.

The error will be thrown on 481 (`my $desc = $descs{$func};`) when `$func="hello"` or something which isn't a key in the hash. You should see the error if you run `duckpan server` and try `excel bogus` as your query.