I was rather thinking of something a bit more structured that would list each variable with its attributes and references broken out.

Do you have an example of such a facility in some other language?

Historically, various tools were used to examine a dump corefile, but I've not seen language-specific nor human-readable dumps before.

Aside from perl variables, all kinds of things will be on the heap for your perl process (eg: things allocated by libraries wrapped in XS interfaces).

-David