elm-language-server: [CoC/neovim] Go to definition fails for some functions

Expected Behavior

I expect “go to definition” to work regardless of the context.

Current Behavior

For some functions, whether they are in the same file or not, I instead get an error from CoC: [coc.nvim] Definition not found

Looking into the log with :CocInfo, this is what I see:

[Info  - 1:54:25 PM] A definition was requested
[Error  - 1:54:25 PM] Request textDocument/definition failed.
  Message: Request textDocument/definition failed with message: anonymousFunctionExprNodes.flatMap is not a function
  Code: -32603

Possible Solution

I have none, sorry!

Steps to Reproduce (for bugs)¶

I don’t have an SSCCE, sorry, but i’ve had the bug occur on my latest pet project, which consists of one Main.elm file, so I figure it’s OK to use it to showcase the issue? Let me know if it is not.

1. git clone --single-branch --branch animation-test git@github.com:Augustin82/0h-n0
2. open ./0h-n0/src/Main.elm
3. go to the use of toColor (l.135) and try to go to definition: it works
4. go to the use of fromColor (l.140) and try to go to definition: it does not work

Context

Going to the definition would be peachy!

Your Environment

• Version used: 1.7.1
• Editor used: neovim
• Environment name and version (e.g. node.js 5.4): nodejs 10.20.1
• Operating System and version: Ubuntu Gnome 18.04