Bash tool returns exit code 1 with no stdout/stderr on CachyOS (Arch Linux)

Description

The Bash tool in Claude Code always returns exit code 1 with no stdout or stderr output for every command, including simple builtins like echo "test", true, whoami, etc.

Commands do execute successfully — this was proven by redirecting output to a file (command > file.txt 2>&1; exit 0) and reading it with the Read tool. The issue is purely with output capture / return.

Environment

• Claude Code version: 2.1.87
• OS: CachyOS (Arch Linux based, kernel 6.19.9-2-cachyos)
• Shell: bash (used by Bash tool), fish (user default), zsh (also installed)
• Architecture: x86_64 (znver4)

Steps to reproduce

1. Install Claude Code on CachyOS
2. Run any Bash tool command, e.g. echo "hello"
3. Result: exit code 1, no output

What was tried (none of these fixed it)

• Setting sandbox.enabled: false in settings.json
• Adding Bash(*) to permissions allow list
• Setting "SHELL": "/bin/bash" in env config
• Adding non-interactive guard to .zshrc ([[ $- != *i* ]] && return)
• Using dangerouslyDisableSandbox: true parameter
• Restarting Claude Code multiple times

Workaround

Redirecting output to a file works reliably:

{ command; } > /home/user/output.txt 2>&1; exit 0

Then using the Read tool to read the file.

Additional context

• The user's zsh config includes Powerlevel10k, oh-my-zsh, and CachyOS-specific zsh plugins — these may interfere with non-interactive output capture
• The Bash tool confirmed it runs under bash (via ps -p $$ -o comm= redirected to file)
• exit 0 is the only "command" that returns exit code 0 normally
• The user reports this worked fine on Bazzite (Fedora-based) previously