I really don't recommend using tryEval in this way... It was very situational in nixvim, and even then still probably wasn't the best solution. As you've pointed out, it has plenty of downsides.

I would recommend trying to find the option by recursively walking the "option attr path" (aka loc), checking each attr for lib.isOption and if true, continuing with opt.type.getSubOptions opt.loc.

getOptionRecursive was the part of the file I was hoping you would take inspiration from 😅

Once you have the actual (sub)option you can make use of opt.isDefined with no hacks needed.

I was just writing some assertions, and wanted to show the option defs for an attr-of an option, isolated using lib.modules.mergeAttrDefinitionsWithPrio.

However, mergeAttrDefinitionsWithPrio only includes the value and highestPrio, with no access to files, definitions, definitionsWithLocations, etc.

I came up with a proof of concept that seems to mostly work, however it's failing nix-build lib/tests/release.nix so is probably not lazy enough?

My question: is there an intended way to print definitions/locations for an attr-of-an-option and, if not, how could I improve my patch to make it PR-ready? Or is there an alternative approach I could take?

In this specific scenario, I'm wanting to showDefs a _module.args.* attr, but the concept could apply to any attrsOf or lazyAttrsOf option.