[BUG] [macOS] Cowork VM rootfs.img download silently fails — "Download already in progress" deadlock prevents workspace from starting

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?

What's Wrong?

After a recent Claude Desktop update, Cowork is permanently stuck at "Starting Claude workspace…" (0%). The root cause is that the app's internal downloader silently fails to download rootfs.img.zst, and on subsequent launches enters a deadlock where it detects "Download already in progress" from a previous failed attempt that no longer exists.

Regular Chat mode works perfectly. Only Cowork, Extensions, and Connectors are affected (all depend on the VM).

What Should Happen?

Cowork workspace should start successfully. The app should download rootfs.img.zst, decompress it, and boot the VM. If a download fails, the app should surface an error to the user and allow a retry — not silently deadlock on a stale download state.

Error Messages/Logs

**Log Pattern (repeats every launch)**


[Bundle:status] rootfs.img missing
[VM:start] Beginning startup, bundlePath=/Users/<user>/Library/Application Support/Claude/vm_bundles/claudevm.bundle
[VM:start] Bundle version: 0ae58222a1f34cf74c74ce47cc717a82a4eb0f25
[VM:steps] download_and_sdk_prepare started
[downloadVM] Download already in progress, waiting...
[Bundle:status] rootfs.img missing
[warm] No warm file found for rootfs.img at current version
[cache] No cached compressed file for rootfs.img
rootfs.img not found, downloading...
Downloading rootfs.img...

Steps to Reproduce

Steps to Reproduce

1. Open Claude Desktop after the update invalidates the existing rootfs.img
2. Click Cowork tab
3. Observe "Starting Claude workspace…" stuck at 0%
4. Check ~/Library/Logs/Claude/cowork_vm_node.log — download never completes

Claude Model

Not sure / Multiple models

Is this a regression?

Yes, this worked in a previous version

Last Working Version

_No response_

Claude Code Version

Latest

Platform

Anthropic API

Operating System

macOS

Terminal/Shell

Terminal.app (macOS)

Additional Information

_No response_