Description

When sandbox.setupCommand is specified as an array of commands in openclaw.json, the array elements are joined without proper newline (\n) separators. This causes multi-command setup scripts to fail with shell syntax errors inside the Docker container.

Steps to Reproduce

1. Set "setupCommand": ["apt-get update", "apt-get install -y curl"] in sandbox config
2. Start a sandbox session
3. The commands are concatenated as apt-get updateapt-get install -y curl instead of being separated by newlines

Expected Behavior

Array elements should be joined with \n to form valid shell script.

Actual Behavior

Array elements are joined without separators, producing invalid shell commands.

Workaround

Local patch that fixes the join separator to use \n:

# Patches sandbox resolver files in dist/

Environment

• Version: 2026.2.25 (still present in 2026.3.1)