[perl #129306] [LTA] “cannot stringify this” error message if the signature is incorrect ( sub foo(@array ($first, @rest)) )

[jn...@jnthn.net via RT]

On Sun Sep 18 17:09:21 2016, alex.jakime...@gmail.com wrote:
> Code:
> sub foo(@array ($first, @rest)) { say @rest };
> foo <1 2 3>
> 
> Result:
> cannot stringify this
> in sub foo at -e line 1
> in block <unit> at -e line 2
> 
> “cannot stringify this” error message is coming from MoarVM. This should not
> happen, right?
> 
> Anyway, it is definitely LTA and could be improved.

Yeah, was a badass umption in the signature binder's error handling code. Fixed 
and now it more helpfully reports:

$ ./perl6-m -e 'sub foo(@array ($first, @rest)) { say @rest }; foo <1 2 
3>;'Type check failed in binding to @rest; expected Positional but got IntStr 
(IntStr.new(2, "2"))
  in sub foo at -e line 1
  in block <unit> at -e line 1

Added a test in S32-exceptions/misc.t.