[BUG] Cowork workspace fails to start on Linux — Electron int3 trap crash after VM bundle download completes

Resolved 💬 4 comments Opened Mar 20, 2026 by andyhunne Closed Mar 20, 2026

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?

I know you don't support Linux (shame, Anthropic, shame...), but I'll file this anyway.

The Cowork workspace consistently fails to start with "Request timed out: isGuestConnected". The VM bundle downloads successfully every time, but the VM never actually boots. The Electron process crashes internally before spawning any KVM/QEMU process.

What Should Happen?

Workspace starts and connects successfully after VM bundle downloads.

Actual behaviour:

[14:38:07] rootfs.vhdx.zst checksum validated — saved to cache
[14:38:09] vmlinuz.zst checksum validated — saved to cache
[14:38:14] initrd.zst checksum validated — saved to cache

Log then goes completely silent — no VM:steps, no start_vm, no wait_for_guest entries. No KVM or QEMU process ever spawns.
dmesg shows the Electron process hitting an int3 breakpoint trap at the exact time the VM boot should occur:

Error Messages/Logs

traps: electron[415028] trap int3 ip:5598b952a8ab sp:7fff418b4590 error:0 in electron[72ad8ab,5598b490d000+9705000]

Steps to Reproduce

  1. Launch Claude Desktop on Linux
  2. Navigate to Cowork / "Let's knock something off your list"
  3. App shows "Starting Claude's workspace..." indefinitely
  4. After ~60 seconds: "Failed to start Claude's workspace — Request timed out: isGuestConnected"

Claude Model

None

Is this a regression?

Yes, this worked in a previous version

Last Working Version

Prior to 1.1.7714...sorry, I didn't capture it.

Claude Code Version

2.1.80 (Claude Code)

Platform

Anthropic API

Operating System

Other Linux

Terminal/Shell

Other

Additional Information

System checks (all passing)

/dev/kvm permissions: crw-rw-rw- (world accessible)
KVM modules loaded: kvm_amd + kvm confirmed via lsmod
virtiofsd installed: yes (Arch extra/virtiofsd 1.13.3-1)
Note: Arch installs virtiofsd to /usr/lib/virtiofsd not /usr/bin/ — symlink created to /usr/bin/virtiofsd

Additional Context

Previous version 1.1.7464 had a different failure: VM timed out on wait_for_guest with virtiofsd socket not ready errors, plus environments-2026-03-01 beta header API rejections blocking Cowork entirely
Version 1.1.7714 fixed the beta header issue but introduced the int3 crash
The new version also changed the VM bundle directory structure from flat claudevm.bundle/ to claudevm.bundle/wvm-<random>/ — unclear if the boot code was updated to match

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