Nimsuggest uses 100% CPU usage with Nim 2.2.0

[xTrayambak]

Description

Related issues:

• nimlsp
• Nix Packages

Ever since NixOS's package cache started compiling nimlsp (and by extension, nimsuggest) against Nim 2.2.0, I've been noticing abnormally high CPU usage coming from nimsuggest, which often requires me to kill the language server (nimlsp) and restart it.

For now, we're circumventing this by forcing nimlsp to compile against Nim 2.0, but this is more of a bandaid fix than anything (we needed to fix this regression before the NixOS 24.11 merge window closed).

Please let me know if you need to know any other information. I'm using NixOS Unstable (24.11 Vicuna) on an AMD CPU, if that matters.

Nim Version

Nim Compiler Version 2.2.0 [Linux: amd64]
Compiled at 2024-10-02
Copyright (c) 2006-2024 by Andreas Rumpf

active boot switches: -d:release

Current Output

No response

Expected Output

No response

Known Workarounds

Compiling nimlsp (and by extension, nimsuggest) against Nim 2.0

Additional Information

No response

[metagn]

Does this happen on any specific code? Or on the development branch?

[xTrayambak]

It occurs in Nim 2.2.0, I haven't tried a development version to see if that works properly. It generally occurs when I open a moderately big file (~700-900 LoC) with various small functions.

[metagn]

Some specific code where this happens would be appreciated, otherwise we can only guess what the issue is. A project is fine too but a minimal example would make it much easier to figure out the problem.

Also, does the same issue happen with nimlangserver?

[michaelnew]

I'm seeing this too after updating to nim 2.2.0. nimlsp will peg to 100% and I have to kill it. nimlangserver fares better, but it will still frequently spike to 100% and stay there for 5 to 10 seconds. This is with neovim 0.10.2, if that matters.

I don't have a minimal repro yet but I'll try to get something together.

[xTrayambak]

I'm using Neovim too, if that matters. I'll link this file as it used to trigger this the most for me. It's around 900-ish lines long and uses templates, if that matters.