rust-analyzer not starting since 5.20.0

[BenSolus]

Have you read the docs and searched existing issues?

• I have read the README's troubleshooting guide and FAQ(https://github.com/mrcjkb/rustaceanvim?tab=readme-ov-file#left_speech_bubble-faq).
• I am using the latest rustaceanvim release.
• I have searched existing issues.
• I have searched existing discussions.
• I have searched the existing issues of other plugins related to this issue (if applicable).
• I have searched the existing rust-analyzer issues (if applicable).
• I can reproduce the issue with stable Neovim (not a distribution or nightly) and the minimal config.
• This is an issue about rustaceanvim, not rust-analyzer or Neovim.
• This is not an issue with autocompletion.

Neovim version (nvim -v)

NVIM v0.10.3

Operating system/version

EndeavourOS

Output of :checkhealth rustaceanvim

rustaceanvim: require("rustaceanvim.health").check()

Checking for Lua dependencies ~
- WARNING dap not installed. Needed for debugging features [mfussenegger/nvim-dap](https://github.com/mfussenegger/nvim-dap)

Checking external dependencies ~
- OK rust-analyzer: found rust-analyzer 1.83.0 (90b35a6 2024-11-26)
- OK Cargo: found cargo 1.83.0 (5ffbef321 2024-10-29)
- OK rustc: found rustc 1.83.0 (90b35a623 2024-11-26)
- OK cargo-nextest: found cargo-nextest 0.9.87
- OK lldb: found lldb version 18.1.8

Checking config ~
- OK No errors found in config.

Checking for conflicting plugins ~
- OK No conflicting plugins detected.

Checking for tree-sitter parser ~
- WARNING No tree-sitter parser for Rust detected. Required by 'Rustc unpretty' command.
- OK .vscode/settings.json loaded without errors.

How to reproduce the issue

In nvim:

:cd cargo-project-root

:e any-rust-file-of-said-project

Expected behaviour

• Diagnostics showing up
• RustLsp command being available

Actual behaviour

With 5.20.1:

• No rust-analyzer process starts according to my system monitor.
• No :RustLsp command
• :RustAnalyzer start seems to do nothing.
• Openin a rust file without cd-ing to the root directory asks if I want to open in standalone-mode, but doesn't seem to do anything after that.
• Even with vim.g.rustaceanvim.server.logfile = /tmp/rustaceanvim.log, no log file gets created.

With 5.20.0:

• When opening a rust file, it opens the rust-anlyzer lsp config.

With 5.19.2, everything I care for works, e.g. expected behavior.

The minimal config used to reproduce this issue.

vim.env.LAZY_STDPATH = ".repro"
load(vim.fn.system("curl -s https://raw.githubusercontent.com/folke/lazy.nvim/main/bootstrap.lua"))()

require("lazy.minit").repro({
    spec = {
        {
            "mrcjkb/rustaceanvim",
            version = '^5',
            -- version = "5.19.2",
            init = function()
            -- Configure rustaceanvim here
            vim.g.rustaceanvim = {}
            end,
            lazy = false,
        },
    },
})

[mrcjkb]

Hey 👋

I just tried to reproduce this with the minimal config you posted (and version = "5.20.1"), and it works just fine on my end.

[BenSolus]

Yeah, I just tried out a docker image of my OS and it works with version = '^5' there.

So I can only think of a problem in my specific setup. But I have no idea what it could be. Any ideas what to test what changed between 5.19.2 and 5.20?

Anyway, as long as 5.19.2 works, while not ideal, I can work with that.

[mrcjkb]

Since version 5.20.0, rustaceanvim tries to auto-detect a running ra-multiplex server.
And if detected, it configures the LSP client to connect to it.
You could try setting vim.g.rustaceanvim.server.ra_multiplex.enable to false. If that solves it for you and you don't use ra-multiplex, then the feature must have somehow introduced a regression that I can't reproduce 🤔

[BenSolus]

That was (kind of) it! I had an old (0.2.2) ra-multiplex installation and when the server ran (ra-multiplex-server in that version), my problems appeared. I am still not sure who on my system still started ra-multiplex since I stopped using it an eternity ago. However, killing the server, updating ra-multiplex to the most recent version (0.2.5) or following your tip with following config

vim.env.LAZY_STDPATH = '.repro'
load(vim.fn.system('curl -s https://raw.githubusercontent.com/folke/lazy.nvim/main/bootstrap.lua'))()

require('lazy.minit').repro {
  spec = {
    {
      'mrcjkb/rustaceanvim',
      version = '^5',
      init = function()
        -- Configure rustaceanvim here
        vim.g.rustaceanvim = {
            server = {
	        ra_multiplex = {
			enable = false,
		}
	    },
	}
      end,
      lazy = false,
    },
  },
}

solved the issue. Thanks 🙂. Should I close this issue with that workaround or do you want to keep it, e.g. trying to catch my case in your plugin?

[mrcjkb]

I'll convert this to a discussion and mark your comment as the answer 😃