Nvim-lspconfig: Rust analyzer going crazy with indexing causing lag

[jacksonludwig]

• nvim --version: latest nightly
• nvim-lsp version(commit hash): 60133c4
• :checkhealth all checks say OK
• What language server(If the problem is related to a specific language server): rust analyzer
• Operating system/version: arch latest version
• Terminal name/version: alacritty
• $TERM: alacritty

How to reproduce the problem from neovim startup

Go to a rust project (preferably one of a larger size that requires more work to index) and type/hold down a key to watch lag. Or use some method to view rust_analyzer's activity and see that it is indexing after every character is typed.

I do not encounter this issue when using coc + coc_rust_anaylzer

[lithammer]

Are you using https://github.com/nvim-lua/completion-nvim as well?

[lithammer]

If so, it might be related to https://github.com/nvim-lua/completion-nvim/issues/203 and/or https://github.com/neovim/neovim/issues/13049.

[jacksonludwig]

Yes I do use it, I will try without completion-nvim and see if there's a difference, thanks.

[gfanto]

I've had the exact same problem with the last version of rust-analyzer and your same setup, and i solved downgrading it, but i haven't checked if it works with coc

[lithammer]

I've actually experienced this myself. Similar to @Fanto94, it started to happen with one of the recent versions of rust-analyzer. It's especially evident if paired with lsp-status.nvim because the statusline flickers with indexing messages on every keypress in insert mode.

[jacksonludwig]

So, I see it indexing on type with coc as well, but there still isn't any lag. It does lag though, with built in lsp regardless if I have completion-nvim or not.

It might be partially rust analyzer's fault and partially built in lsp not handling it well.

[LesnyRumcajs]

@lithammer Were you able to find a workaround for this? I updated today my plugins and this indexing window is popping for every key press in Insert.

[lithammer]

Unfortunately not. It's unclear to me if it's a Neovim LSP, lsp-status.nvim issue or rust-analyzer issue. But for example if I open a project with VS Code the statusbar shows a constantly spinning cogwheel with the message "Starting".

It might just be an issue with the vscode-rust plugin, but almost makes it sound like it doesn't 100% finish the startup phase?? On the other hand, VS Code isn't flickering with "Indexing ..." messages when typing. But that might just be due some debouncing and/or buffering of the progress messages.

But given that the problem started by an upgrade of rust-analyzer, I suspect maybe an issue should be raised on their issue tracker as well.

Here's a gif of the problem:

[LesnyRumcajs]

@lithammer Thanks for the reply.

I had an even more annoying constantly popping floating window with this indexing. I got rid of it by rolling back the coc.nvim update to 806ce47583d66d0b574a3c993526033971e700cf.

[etrnal70]

Anybody got a clue for this ? Large project are extremely slow on my end and it's even barely usable

[kid]

I have been experiencing slowdowns as well, disabling lsp-status seems to have resolved them, Don't know if that's because of lsp-status or how it's called from vim-airline in my case