Rust-analyzer times out when a large buffer is open.

What’s the output of :CocInfo

vim version: VIM - Vi IMproved 8.1 8012269
node version: v12.22.7
coc.nvim version: 0.0.80-cf98cf301f
coc.nvim directory: /home/jakew/.vim/bundle/coc.nvim
term: dumb
platform: linux

## Log of coc.nvim

2021-11-18T09:30:01.389 INFO (pid:1544) [plugin] - coc.nvim 0.0.80-cf98cf301f initialized with node: v12.22.7 after 43ms
2021-11-18T09:30:03.860 INFO (pid:1544) [services] - registered service "rust-analyzer"
2021-11-18T09:30:03.860 INFO (pid:1544) [services] - Rust Analyzer Language Server state change: stopped => starting
2021-11-18T09:30:03.889 INFO (pid:1544) [language-client-index] - Language server "rust-analyzer" started with 1567
2021-11-18T09:30:03.896 INFO (pid:1544) [services] - Rust Analyzer Language Server state change: starting => running
2021-11-18T09:30:03.902 INFO (pid:1544) [services] - service rust-analyzer started
2021-11-18T09:30:17.879 INFO (pid:1544) [completion-complete] - Results from: around,rust-analyzer
2021-11-18T09:33:02.607 INFO (pid:1544) [completion-complete] - Results from: around,buffer
2021-11-18T09:33:54.483 INFO (pid:1544) [attach] - receive notification: runCommand [ 'rust-analyzer.serverVersion' ]
2021-11-18T09:35:00.418 INFO (pid:1544) [attach] - receive notification: showInfo []
2021-11-18T09:37:07.566 INFO (pid:1544) [completion-complete] - Results from: around,buffer
2021-11-18T09:37:59.867 INFO (pid:1544) [attach] - receive notification: showInfo []

What’s the output of :CocCommand rust-analyzer.serverVersion [coc.nvim] rust-analyzer 73668334f 2021-11-15 stable

My tests have some large files that they open (about 80k line csv). When I:

1. Open lib.rs in my rust project into a buffer.
2. Open tests/input/large.csv into another buffer.
3. Make a change to lib.rs.
4. Save the change.

Vim will hang for a while and then give the message: “rust-analyzer timeout after 5000ms”.

[jacwellington]

I figured out that if I tell coc-list to ignore buffers this problem goes away. I did that by using the :CocConfig command and putting this in my settings file:

{
        "coc.source.buffer.enable": false
}

[jacwellington]

I figured out the source of the problem. I believe it is the set hidden setting that is triggering this for some reason. Here is a minimal vimrc that I used in order to recreate the behavior:

set nocompatible
set hidden
filetype off
set rtp+=~/.vim/bundle/Vundle.vim
call vundle#begin()
" let Vundle manage Vundle
" required!
Bundle 'gmarik/vundle'

" My Bundles here:
"
" original repos on github
Bundle 'neoclide/coc.nvim', 'release'
Bundle 'rust-lang/rust.vim'

call vundle#end()
filetype plugin indent on     " required!

syntax on

If I remove set hidden then everything works fine. Any idea why this might be?