E5108: Error executing lua /usr/share/nvim/runtime/lua/vim/lsp/handlers.lua:438: bad argument #2 to 'format' (number expected, got nil)

hello there!

sorry for the giant issue name. i wanted to make it easy to search for later (anyway i can edit it). and maybe this might be lsp problem itself and not kls (sorry again).

when using :lua vim.lsp.buf.implementation() on a Kotlin interface, the output is: E5108: Error executing lua /usr/share/nvim/runtime/lua/vim/lsp/handlers.lua:438: bad argument #2 to 'format' (number expected, got nil). the same does not occur when using on a TypeScript interface (with tsserver obviously), and that’s why i am opening the issue here and not at lsp-config codebase.

i am running

• NVIM v0.6.0-dev+434-g7f93b2ab0
• kotlin-language-server 4963762 commit

am i missing anything? could anyone help me please?

EDIT 1 My lsp-config:

lua require'lspconfig'.kotlin_language_server.setup{ on_attach = require'completion'.on_attach }

[mjlbach]

This is now fixed in neovim

[fwcd]

From what I can tell, this looks like a bug in the Neovim LSP client rather than a KLS bug. Looking at the corresponding line, it seems as if the client_id is missing. Googling the issue suggests that the problem is having multiple language servers attached to the buffer:

• https://www.reddit.com/r/neovim/comments/papp9d/nvimlsp_help_tracking_down_an_error_when/
• https://github.com/neovim/neovim/pull/15193
• https://github.com/neovim/neovim/pull/15469