[bug] Ensure tmux uses bash (or bash like)

[mvancanneyt]

BMAD layout

current (_bmad/bmm/4-implementation)

OS

Ubuntu/macos

Python version

not applicable

Node version

not applicable

Exact command

I am using tcsh.

The automator uses tmux to spawn sub agents. It sometimes sends bash syntax to the tmux terminal, which fails because the default shell used by tmux is my login c shell (which is what I generally want).

The solution is simple: when launching tmux, give it the default-shell /bin/bash command, something like

tmux set-option -g default-shell /bin/bash

it should not hurt any other users.

Claude code usually figures out to do this, but only after burning a huge amount of tokens.

alternatively, tell it to ensure somehow that a bash-compatible shell is running. It should normally do the above by itself then.

(for reference, claude code actually runs its commands using bash)

Install path type

not applicable / unknown

Installed tag, branch, or package version

not applicable

Target tool

claude-code

YAML install manifest

not applicable

CSV install manifest

not applicable

Exact installer stdout/stderr

not applicable

Expected behavior

Agent ensures that the tmux session runs bash and any script it sends works.

Actual behavior / error output

Agent assumes that the tmux session runs bash, but any script it sends fails with syntax errors.