[perl #76742] Mixing into the type object gives LTA error message

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# New Ticket Created by  Moritz Lenz 
# Please include the string:  [perl #76742]
# in the subject line of all future correspondence about this issue. 
# <URL: http://rt.perl.org/rt3/Ticket/Display.html?id=76742 >


10:50 < moritz_> rakudo: Bool does role { method Str() { $.perl } }; say
                  ~Bool::True
10:50 <+p6eval> rakudo 9808d7: OUTPUT«Attempt to use rebless_subclass 
where the new class was not a subclass␤  in 'infix:<does>' at line 
6379:CORE.setting␤  in 'infix:<does>' at line 525:CORE.setting␤
                 in main program body at line 22:/tmp/vsMNEIdThV␤»