[perl #63458] Null PMC access in isa() when calling non-existant rule

[Vasily Chekalkin via RT]

On Wed Feb 25 00:49:42 2009, ml...@physik.uni-wuerzburg.de wrote:
> 09:45 <@moritz_> rakudo: sub m (&f) { say "a" ~~ m/<f>/ }; regex outer {
> a };
>                  m(&a)
> 09:45 < p6eval> rakudo 7f8ba6: OUTPUT«Null PMC access in isa()␤current
> instr.:
>                 '!SIGNATURE_BIND' pc 2559
(src/classes/Signature.pir:377)␤»
> 
> note that there's no rule named 'a' defined.
> 
> A more helpful error message would be appropriate.
> 
> Moritz
> 

Patch available at 
http://github.com/bacek/rakudo/commit/6a68c91cf0311df9472886caefef750fb2503df4

Now it produces this:
$ ./perl6 -e 'sub m (&f) { say "a" ~~ m/<f>/ }; regex outer { a }; m(&a)'
Non-Callable argument for f in call to m

-- 
Bacek