Haskell extension triggers an error when trying to initiate a rename

[isomorpheme]

Summary

When trying to rename an identifier in Haskell code, nothing happens and I get this error instead:

Invalid for language server to send a `defaultBehavior` response to `prepareRename`

Steps to trigger the problem:

1. Open a Haskell project (haskell-language-server version: 2.9.0.0 (GHC: 9.6.6)).
2. Make sure HLS is otherwise functioning.
3. Try to rename an identifier (e.g. a top-level function).

Actual Behavior:

The rename input never appears and I get an error.

Expected Behavior:

I'm allowed to enter the new name as usual.

---

This could very well be an upstream problem of HLS not correctly implementing the language server protocol. But things were working fine until a few versions ago, so I'm not sure if Zed needs to be that strict about it. haskell/haskell-language-server#3130 might also be related, though this also happens for identifiers in modules with an explicit export list that are not exported.

Zed Version and System Specs

Zed: v0.171.4 (Zed)
OS: Linux Wayland ubuntu 24.04
Memory: 30.8 GiB
Architecture: x86_64
GPU: Intel(R) Arc(tm) Graphics (MTL) || Intel open-source Mesa driver || Mesa 24.0.9-0ubuntu0.3

[probably-neb]

I agree with you it seems like hls is returning an invalid/unexpected response that we should probably consider being less strict about. Thanks for reporting this!

[osiewicz]

This is just a LSP spec incompatibility (we don't support defaultBehavior). There was actually a recent fix for Gleam where prepareRename did not work for them either.
Granted, a language server should check with the capabilities we send out to see if they can use DefaultBehaviour in the first place.. so it's also a bug on Haskell Language Server side too :)