Bug with "content" keyword but can't find why (neovim)

[rambip]

I just encountered a strange bug in the lsp server.

I use the neovim configuration with built-in lsp, it may be the source of the issue but I'm not sure.

The error is pretty easy to replicate with neovim:

Copy and paste the configuration from the wiki to your vimrc or init.luaf

And then:

mkdir error
cd error
echo "package error" > error.ipkg
echo "modules = error" >> error.ipkg

echo "content = error_not_defined" > error.idr 
nvim error.idr

I get this strange error:

Error executing luv callback:
/usr/share/nvim/runtime/lua/vim/lsp/rpc.lua:601: /usr/share/nvim/runtime/lua/vim/lsp/rpc.lua:1
32: invalid header line "content\27[0;1m.\27[0m\
\
\27[38;5;12merror:1:1--1:28\27[0m\
 \27[38;5;12m1 |\27[0m content = error_not_defined\
     \27[38;5;9;1m^^^^^^^^^^^^^^^^^^^^^^^^^^^\27[0m\
\
Content-Length: 317"

It turns out the "content" keyword make the lsp communication break at one point, because it appears in the rpc communication.

I don't know how to check what part is wrong, what do you think is more probable:

• This is entirely a neovim bug
• This is entirely a idris2-lsp bug
• They are both not 100% robust and we're not lucky.

If someone has experience with nvim-lsp, it would be great if he could look what is wrong (or help me debug it).

[ShinKage]

I've replicated the issue and looked at the logging. If my understanding is correct, is an issue with both client and server.
From the idris2-lsp side the issue is upstream with the compiler. Even though the compiler API exposes a functions that builds file and collects the errors, it still print the errors on the stdout while collecting, a behaviour that should be changed.
Normally, the neovim client implementation is robust enought to ignore those stray messages on the stdout, however it seams that the content or something else in that error messages trips the client.
As a hack this can be potentially solved by redirecting stdout to /dev/null, using another channel to output the server messages and then redirect that channel to stdout.

[rambip]

So I link to my issue for neovim, I hope that can help.

neovim/neovim#15444