[perl #131584] [REGERSSION] EXPORTHOW SUPERSEDE/DECLARE Cannot invoke this object

[via RT]

# New Ticket Created by  Lloyd Fournier 
# Please include the string:  [perl #131584]
# in the subject line of all future correspondence about this issue. 
# <URL: https://rt.perl.org/Ticket/Display.html?id=131584 >


cat >A.pm6 <<'END'
my package EXPORTHOW {
    package DECLARE {
        constant pokemon = Metamodel::ClassHOW;
    }
    package SUPERSEDE {
        constant grammar = Metamodel::ClassHOW
    }
}
END
perl6 -I. -e 'use A;'

===SORRY!===
Cannot invoke this object (REPR: Null; VMNull)

This is Rakudo version 2017.05-454-g5facb26 built on MoarVM version
2017.05-85-g21ee1a5
implementing Perl 6.c.