With asdf-3.1.4, how do I introspect the current state of source registry configuration? I need to debug a remote user's ASDF configuration on a machine which I don't have access to, so I would like to have ASDF output the current source registry configuration search state. Problematically, the behavior documented in section 8.1 doesn't seem to be working as described on the user's machine. And this behavior seemingly changes between "patch level" ASDF releases especially on marginal platforms like Windows, digging up the "correct" version of the manual isn't so easy either.
[1]: https://common-lisp.net/project/asdf/asdf.html#Controlling-where-ASDF-search...
The contents of ASDF/SOURCE-REGISTRY:*SOURCE-REGISTRY* provides a hashtable of systems that ASDF has located, but doesn't help me figure out where ASDF *might* have searched for things. For output translations the return value of (ASDF:INITIALIZE-OUTPUT-TRANSLATIONS) gives me enough information for output translations, so it would be nice to have something equivalent for the source registry. Since I suppose that all of the behavior specified in section 8.1 is not easily transcribed as a s-expr, my request may not be trivial to implement, but in lieu of some similar mechanism, I am really having problems with debugging ASDF behavior in a particular instance.
Additionally, what is the behavior of ASDF when the $XDG_* environment variables are not set, as is seemingly the case on a stock Windows environment? Are these configuration steps just skipped?