The error has something to do with lack of ref counting of the stack.
Well, that is asserted in https://rt.perl.org/rt3/Public/Bug/Display.html?id=77706 but no justification or even discussion of that assertion is apparent or even linked from it and I find the assertion not credible. Items on the stack in Perl are still ref-counted, just somewhat differently. There may be a fundamental flaw in this difference but I have not heard it described and it is not apparent to me.
If you run into some actual discussion or even a description that is not ridiculously vague, please point such out.