Muddling along with my project, I took two approaches:

1. I took out a circular link, which was necessary anyways, to avoid global destruction.
2. I'm no longer blessing $perldata- I'm oldschool enough to have learned on Perl4 anyways.

If I understand your explanation correctly, using a blessed or unblessed version of $perldata may only re-arrange an indeterminate destruction order, and therefore not a reliable solution. But then you took the same approach with your command line switch... Can you explain?

I also tested with the following code:

superman::DESTROY {
  warn "Blasted Kryptonite" ;
  }
[download]

Based on my observation, the superman object is destroyed when expected, after all the referencing objects. It's not that the references point to a destroyed object so much as the references themselves are getting clobbered. I'm probably digging too deep- If I have to think this hard in Perl, I must be taking the wrong approach.

Finally, thanks for the heads up about weak references. I was not aware of them.