Location data lost?

I often find merlin has a hard time with locations when using `get_in` - this could just be on my side, but thought I'd ask in case it's a known issue.

Start by reproducing the reported location problem when using `get_in` with merlin. The issue names no files, tests, or expected behavior, so first determine whether location data is actually lost and identify the relevant entry point before defining what a fix would need to demonstrate.

Written by the indexing model from the issue text.