The Vscod* extension fails to start the LSP because I use tmux as my default terminal

[idkidk000]

Description

Ruby LSP Information

Collect Ruby LSP information for issue reporting throws No active Ruby workspace found, presumably because the LSP won't start.

• extension version 0.10.0 of the extension installed from https://open-vsx.org/extension/Shopify/ruby-lsp
• Vscodium version 1.109.01000 .deb install from https://github.com/VSCodium/vscodium
• I have a wrapper script which connects to or starts a per-project tmux session as my default terminal. This is for me. If the extension needs a terminal, it should use bash directly since that will provide a regular shell. tmux will not do that.

Reproduction steps

1. Write a small wrapper to launch tmux and set the executable bit:

/home/user/.local/bin/vscodium-tmux

#!/usr/bin/env bash
declare project
read -r project < <(basename "$PWD")
exec tmux new-session -ADs "$project"

2. Add a custom terminal profile for the script and set it as the default:

settings.json

  "terminal.integrated.defaultProfile.linux": "tmux",
  "terminal.integrated.profiles.linux": {
    "bash": {
      "icon": "terminal-bash",
      "path": "bash"
    },
    "tmux": {
      "path": "/home/user/.local/bin/vscodium-tmux"
    }
  },

3. Restart Vscod*, open a Ruby project and try to to (re)start the Ruby LSP. It produces the output below and remains in the Starting state indefinitely:

2026-03-04 10:11:10.511 [info] (ProjectName) Running command: `/home/user/.rbenv/bin/ruby -EUTF-8:UTF-8 '/home/user/.vscode-oss/extensions/shopify.ruby-lsp-0.10.0-universal/activation.rb'` in /home/user/Code/3p/ProjectName using shell: /home/user/.local/bin/vscodium-tmux

---

It may be that there's a setting I can change, but the troubleshooting guide is a bit vague. I need the extension to use bash directly rather than my default terminal. I don't think that it's correct to use my configured default terminal (for the UI) in this way.

---

Edit: I failed to mention that setting my default terminal to bash in my settings.json for Ruby projects fixes the issue and the extension works perfectly. And it's a really nice extension!

[gstokkink]

Running into this as well. I want to use a default profile for my terminal that uses tmux and therefore is not compatible with ruby-lsp (apparently). I tried configuring terminal.integrated.automationProfile.osx to use zsh directly instead, but it looks like ruby-lsp ignores that setting and uses the default terminal profile instead. I think that's incorrect?

Versions used

VS Code: 1.111.0 (Universal)
Ruby LSP: 0.26.8
Ruby LSP Rails: 0.4.8

[gstokkink]

I fixed it for now by configuring a custom script to launch my tmux stuff:

    "terminal.integrated.profiles.osx": {
        ...
        "vsc-mux": {
            "path": "vsc-mux",
            "args": []
        }
    },
    "terminal.integrated.defaultProfile.osx": "vsc-mux",

And in this script I check the TERM_PROGRAM ENV var, which is set for regular terminals but not when Ruby-LSP launches the 'shell'. If it's not set, I simply pass the arguments along to zsh:

if [[ -z "${TERM_PROGRAM:-}" || "$TERM_PROGRAM" != "vscode" ]]; then
  zsh -c "$@"
else
  tmux ...
fi