[perl #67818] [BUG] Cannot instantiate subtype of Array or Hash in Rakudo

[Carl Mäsak]

# New Ticket Created by  "Carl Mäsak" 
# Please include the string:  [perl #67818]
# in the subject line of all future correspondence about this issue. 
# <URL: http://rt.perl.org/rt3/Ticket/Display.html?id=67818 >


<masak> rakudo: subset Person of Hash where { .keys.sort ~~ <firstname
lastname> }; my Person $p = { :firstname<Kyle>, :lastname<Ha> }
<p6eval> rakudo f5ccc0: OUTPUT«Could not build C3 linearization:
ambiguous hierarchy␤in sub trait_mod:of [...]
<masak> I think I just found a bug. \o/
<masak> jnthn: seen something like this before?
<jnthn> not seen that one before... :-S
<jnthn> report
<masak> rakudo: subset Person of Hash; my Person $p = {}
<p6eval> rakudo f5ccc0: OUTPUT«Could not build C3 linearization:
ambiguous hierarchy␤in sub trait_mod:of [...]
* masak reports
<masak> rakudo: subset Austria of Array; my Austria $p = []
<p6eval> rakudo f5ccc0: OUTPUT«Could not build C3 linearization:
ambiguous hierarchy␤in sub trait_mod:of [...]
<masak> rakudo: subset Meercat of Pair; my Meercat $p = :a<b>
<p6eval> rakudo f5ccc0:  ( no output )
<masak> rakudo: subset Austria of List; my Austria $p = []
<p6eval> rakudo f5ccc0:  ( no output )

So subtyping Pair and List works, but not subtyping Array or Hash.