[perl #122220] "@list is copy" leads to dependent default parameters not updating

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# New Ticket Created by  Peter 
# Please include the string:  [perl #122220]
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# <URL: https://rt.perl.org/Ticket/Display.html?id=122220 >


10:37   ren1us  m: sub a(@list is copy, $l = @list.elems) { say "Elems: " ~ 
@list.elems; say "l: $l"; }; a(<a b c d e f g>); a(<a b c>);
10:37   camelia rakudo-moar cce7f9: OUTPUT«Elems: 7␤l: 7␤Elems: 3␤l: 7␤»
10:37   ren1us  m: sub a(@list, $l = @list.elems) { say "Elems: " ~ 
@list.elems; say "l: $l"; }; a(<a b c d e f g>); a(<a b c>);
10:37   camelia rakudo-moar cce7f9: OUTPUT«Elems: 7␤l: 7␤Elems: 3␤l: 3␤»
10:45   colomon_        sure looks like a rakudobug
10:45   * ren1us        submits
10:47   jnthn   What the thunk...
10:48   jnthn   I think the first one goes through the slow-path binder thanks 
to the "is copy"
10:49   ren1us  m: class A { method test(@list is copy, $l = @list.elems) { say 
"Elems: " ~ @list.elems; say "l: $l"; }; }; my $a = A.new; $a.test(<a b c d e f 
g>); $a.test(<a b c>);
10:49   camelia rakudo-moar cce7f9: OUTPUT«Elems: 7␤l: 7␤Elems: 3␤l: 7␤»
10:49   jnthn   So the bug is probably in there.