Earlier quoted context omitted.
> Perl 6 is probably a great language, Does it also have the unparseability problem[0] of Perl 5? That's a deal breaker for a lot of tooling. [0] https://perlmonks.org/?node_id=663393
This specific problem is not a deal breaker in practice. You solve the problem by adding to the readme of the tool "If the arity of a function cannot be established, we assume no arguments and print an warning. Add {foobar} before the function to assume arguments. Sorry for inconvenience." No language tooling is perfect. We shouldn't expect that from Perl tooling either.
Java and C# tools are pretty close. But yeah, it's generally hard for dynamic languages.