From @masak

This be Rakudo db84bc on Parrot r43174.

$ perl6 -e 'class A { method foo() { self = 5 } }; my A $a = A.new;
$a.foo; say $a; say $a.WHAT'
5
Int()

I'm not sure 'self' should be a writable lvalue in the first place.
But if it's supposed to be, I'd still think that the above ought to be
disallowed for some reason. Note that the above manages to sneak an
Int into variable typed to only contain A objects.

From @pmichaud

In the new master branch, self is no longer writable. I don't know if
we need a test for this ticket before closing it (I suspect we do).

Pm

The RT System itself - Status changed from 'new' to 'open'

From @moritz

now tested in S12-class/basic.t.

@moritz - Status changed from 'open' to 'resolved'