From @masak

<masak> rakudo​: my @​a = a => 1, b => 2; for @​a -> Pair $p ( $key,
$value ) { say $key }
<p6eval> rakudo 6c9731​: OUTPUT«Not enough positional parameters
passed; got 0 but expected 2 in sub-signature of parameter $p [...]
<jnthn> rakudo​: my @​a = a => 1, b => 2; for @​a -> Pair $p ( :$key,
:$value) { say $key }
<p6eval> rakudo 6c9731​: OUTPUT«Mu()␤Mu()␤»
<jnthn> hmm
<jnthn> rakudo​: (a => 1).^attributes>>.has_accessor>>.say
<p6eval> rakudo 6c9731​: OUTPUT«Bool​::False␤Bool​::False␤»
<jnthn> ah.
<jnthn> masak​: Are you going to masakbug the above?
<jnthn> masak​: I'm compiling a patch now but it deserves a test.
<jnthn> masak​: And getting you to submit a bug report is the laziest
way I can make sure it gets tested :P
* masak submits rakudobug, on request
<masak> jnthn​: I'm sorry, I woulda done it sooner. I was sure that one
had an RT ticket already.
<masak> I mean, how could it not? it's been known for ages.
<masak> seems there isn't one, so here goes.

From @moritz

Works now, and tested in the new S06-signature/unpack-object.t file.

@moritz - Status changed from 'new' to 'resolved'