I tried to run your solution without {-# LANGUAGE ImportQualifiedPost #-} and tests passed. You also need to change import Data.Traversable qualified as T to import qualified Data.Traversable as T

Still did not fix

Try to add {-# LANGUAGE Haskell2010 #-} and fix compilation errors. It seems the issue is because of lib used to validate imports. It fails if code is not a valid Haskell2010.

I'm having the same trouble as the user below me. My solution is correct and I'm not using any Lens imports but I'm getting the following error:
uncaught exception: IOException of type UserError
user error (Could not parse solution correctly)

I'm also getting this error but i DO have RankNTypes enabled..

Oh, Agda. Didn't realise the kata was available in multiple languages, sorry.

What?

language?

The open Language {{...}} line in the template should be made public so that the tests work.

I see. RankNTypes should be made available for TupleSections to work. The above error will occur when {-# LANGUAGE RankNTypes #-} is missing. Sorry for the stupid question.

How to avoid the following error on the test case Cannot use Control.Lens? I did not import anything that relates to Control.Lens.

uncaught exception: IOException of type UserError
user error (Could not parse solution correctly)

Also known as a difference list. If you're looking for hints, Hughes lists, when run, will not overwrite the list they take as an input.

Very scary, but surprisingly pretty easy, just follow the types (some of them are singletons !)

Really nice kata, thanks tel !

It is satisfctory, but I wish it could give more thorough explanation and type replacements.
Especially, how each part of it works. (And what actually is a profunctor)

[...] suggests that it receives a function (Name -> Maybe String) and returns another function (Phalanx -> Maybe String)

which is true with and without the parentheses because of Haskell's autocurrying. But I agree that the parentheses should be omitted as they do nothing.