Investigated this a bit more. I guess there is a limitation of the YAML test approach for prune tests, as the the prefix records need dependency metadata. The prune tests can't be expressed as YAML with the current framework at least, since dist strings don't carry dependency information.

I'm going to keep this as a draft for now: as the prune tests are inherently multi-step (first solve, then use records as prefix, second solve with prune) and I don't fully know how to make this work with yaml tests... might close it later