From @masak

<poor_soul> is it ok for this to crash?
<poor_soul> r​: enum A (a=>3,b=>10,c=>1); class B { BEGIN for
A.enums.kv -> $k, $v { our $k :​:= $v }; }; say B.b
<camelia> rakudo 69c3cc​: OUTPUT«===SORRY!===␤Null PMC access in get_bool()␤»
<tadzik> certainly not in this way
<masak> poor_soul​: certainly not ok.
* masak submits rakudobug
<mathw> "Null PMC access" is always a bug, IIRC
<moritz> overwriting B​::k with each enum value in turn doesn't sound too useful
<poor_soul> i was trying to find a way to declare constants in a class
based on a enum
<jnthn> poor_soul​: Does declaring the enum in the class not do it? :)
<poor_soul> jnthn​: it does only partially, since if i want to use it,
i need to put the name of the enum
<jnthn> r​: class A { enum B <c d e>; method m() { say e } }; A.m
<camelia> rakudo 69c3cc​: OUTPUT«e␤»
<jnthn> r​: class A { enum B <c d e>; method m() { say +e } }; A.m
<camelia> rakudo 69c3cc​: OUTPUT«2␤»
<masak> r​: enum A (a=>3); class B { BEGIN for A.enums {} } # golf'd
<camelia> rakudo 69c3cc​: OUTPUT«===SORRY!===␤Null PMC access in get_bool()␤»
<masak> ooh, in fact...
<masak> r​: enum A (a=>3); BEGIN for A.enums {}
<camelia> rakudo 69c3cc​: OUTPUT«===SORRY!===␤Null PMC access in get_bool()␤»
<jnthn> Short names seem to work to me.
<jnthn> r​: enum A (a=>3); BEGIN A.enums
<camelia> rakudo 69c3cc​: ( no output )
<jnthn> r​: enum A (a=>3); BEGIN A.enums.perl.say
<camelia> rakudo 69c3cc​: OUTPUT«("a" => 3).hash␤»
<jnthn> r​: enum A (a=>3); BEGIN { for A.enums { }; 1 }
<camelia> rakudo 69c3cc​: ( no output )
<jnthn> r​: enum A (a=>3); BEGIN { for A.enums { } }
<camelia> rakudo 69c3cc​: ( no output )
<jnthn> r​: enum A (a=>3); BEGIN for A.enums { }
<camelia> rakudo 69c3cc​: OUTPUT«===SORRY!===␤Null PMC access in get_bool()␤»
<jnthn> wow...you need the blockless form to trigger it.

From @usev6

There is still a Null PMC access on Parrot. On Moar and JVM it runs fine​:

$ perl6-p -e 'enum A (a=>3); BEGIN for A.enums { }'
===SORRY!===
Null PMC access in get_bool()

$ perl6-m -e 'enum A (a=>3); BEGIN for A.enums { }; say "alive"'
alive

$ perl6-j -e 'enum A (a=>3); BEGIN for A.enums { }; say "alive"'
alive

I added a test (fudged 'skip' for Parrot) to S04-phasers/begin.t with commit Raku/roast@489ebb2e46.

@usev6 - Status changed from 'new' to 'open'

From @usev6

Since support for Parrot was suspended with Rakudo Star Release 2015.02, I'm closing this "parrot only" ticket.

I added the ticket to a list of closed ticket living in the Mu repository​: https://github.com/perl6/mu/blob/master/misc/rt.perl.org/tickets_closed_parrot_only.txt.

In case support for Parrot will be restored in some future release the listed tickets can be checked and re-opened as appropriate.

@usev6 - Status changed from 'open' to 'rejected'