Cowork: persistent 'useradd failed: exit status 12: cannot create directory /sessions/' error

Bug Description

Claude Cowork sessions consistently fail to start with the following error:

RPC error: ensure user: useradd failed: exit status 12: useradd: cannot create directory /sessions/blissful-exciting-bell

Details

• Started: April 4, 2026
• Frequency: Every attempt, persistent (not transient)
• Platform: macOS (Darwin 25.4.0)
• Install method: Native + npm
• Claude Code version: Latest (updated April 5, 2026)
• GitHub account: khary-ai

Expected Behavior

Cowork session should provision successfully and create the session directory under /sessions/.

Actual Behavior

useradd fails with exit status 12 ("cannot create home directory"), suggesting the /sessions/ directory on the server node is missing, full, or has incorrect permissions.

Reproduction

Attempting to start any Cowork session triggers this error consistently. Multiple retries over 24+ hours have not resolved it, suggesting a persistent infrastructure issue rather than a transient failure.