[BUG]All cowork sessions failing: "no space left on device" and "useradd failed"

Preflight Checklist

• [x] I have searched existing issues and this hasn't been reported yet
• [x] This is a single bug report (please file separate reports for different bugs)
• [x] I am using the latest version of Claude Code

What's Wrong?

Description

All cowork sessions (new, scheduled, and previously working tasks) are failing with infrastructure errors. This affects every session type — nothing runs.

Error Messages

RPC error: failed to mount /mnt/.virtiofs-root/shared/Library/Application Support/Claude/local-agent-mode-sessions/.../shim-perm/requests as .cowork-perm-req: failed to create mount point: mkdir /sessions/exciting-beautiful-keller/mnt/.cowork-perm-req: no space left on device

RPC error: ensure user: useradd failed: exit status 12: useradd: cannot create directory /sessions/happy-sharp-brown

Details

Platform: macOS (Darwin 25.3.0)
Issue started: 2026-04-02
Affects: All task types — new conversations, scheduled tasks, and resuming old tasks
No scheduled tasks are active (confirmed via list_scheduled_tasks)
Local disk has plenty of free space — the issue is in the remote container provisioning
Expected behavior

Sessions should provision and mount successfully.

Actual behavior

Every session fails immediately with disk space errors in the server-side container.

What Should Happen?

coworker should work like it did yesterday,

Error Messages/Logs

RPC error: failed to mount /mnt/.virtiofs-root/shared/Library/Application Support/Claude/local-agent-mode-sessions/823f6874-6252-4031-ae4e-a3c22d37598e/f6b75d02-cca9-4943-ad6e-88390a3f201d/local_09defce7-c93b-4b79-8fc2-8aa2657ba16b/shim-perm/requests as .cowork-perm-req: failed to create mount point: mkdir /sessions/exciting-beautiful-keller/mnt/.cowork-perm-req: no space left on device

RPC error: ensure user: useradd failed: exit status 12: useradd: cannot create directory /sessions/happy-sharp-brown

Steps to Reproduce

1. Try to initiate any coworker test, past, new, present or scheduled

Claude Model

Opus

Is this a regression?

Yes, this worked in a previous version

Last Working Version

_No response_

Claude Code Version

Claude Code version is 2.1.87.

Platform

Anthropic API

Operating System

macOS

Terminal/Shell

Terminal.app (macOS)

Additional Information

_No response_