I have always used ASDF:*CENTRAL-REGISTRY*, with some local code that grovels over source trees.
I'd love to stop maintaining the tree groveler, and move to the DSL, but I have never understood how you debug the DSL when ASDF fails to find your system.
With *CENTRAL-REGISTRY* you pretty much pprint the variable, eyeball it, and it's usually pretty easy to see whether a directory is missing.
But what do you do if you use the DSL? The last time I tried to use the DSL, I found myself using the inspector to grovel over internal-to-ASDF hash tables, which wasn't very pleasant.
Is there a "debugger API" to the new source configuration search? E.g., can we dump the hash-table in a human readable (sorted, formatted way?)? can we trace something to see how ASDF is populating the hash table?
cheers, r