Cowork: "Failed to create bridge sockets after 5 attempts" on every new task (Claude Desktop 1.3036.0, Claude Code 2.1.111, macOS 26.3.1 ARM)

Summary

Every new cowork task fails within ~1 second of spawn with:

Error: Failed to create bridge sockets after 5 attempts

This looks related to #19503 (resume-only bug) and #23746 (1.1.2156 regression, closed as duplicate), but my repro differs: new tasks, not resumes, and allowedDomains=23 — so neither root cause there matches. Still happening on the latest Claude Desktop.

Environment

• Claude Desktop: 1.3036.0
• Claude Code (in-VM SDK): 2.1.111 (sha256 prefix 99376866bf7ec367)
• macOS: 26.3.1 (ARM64 / Apple Silicon)
• VM bundle version: 5680b11bcdab215cccf07e0c0bd1bd9213b0c25d

Repro

1. Open Claude Desktop.
2. Start a brand-new cowork task (no resume).
3. Task exits ~1s later with the bridge-sockets error.

Reproduces 100% of the time across 5+ fresh VM boots.

Log evidence

From ~/Library/Logs/Claude/cowork_vm_node.log:

[Spawn:config] Creating spawn function for process=compassionate-wonderful-wozniak,
  isResume=false, mounts=7 (outputs, .claude, .claude/skills, .cowork-lib,
  .cowork-perm-req, .cowork-perm-resp, uploads), allowedDomains=23
[Spawn:create] ... cmd=/usr/local/bin/claude args=... --permission-prompt-tool stdio
  --allow-dangerously-skip-permissions ... cwd=/sessions/compassionate-wonderful-wozniak
[Spawn:vm] OAuth token approved with MITM proxy
[Spawn:vm] Spawn succeeded in 45ms
[vm-stderr ...] Error: Failed to create bridge sockets after 5 attempts
[Process:...] Exited, code=1, signal=null, duration=948ms, oom=false

VM side (coworkd.log) shows clean boot: gvisor network up, static IP assigned, MITM proxy started on /var/run/mitm-proxy.sock, OAuth token approved. Failure is entirely inside the spawned claude process.

Root of the error is Claude Code's own sandbox bridge setup (u57() in the bundled JS) — it spawns two socat processes for HTTP/SOCKS unix-to-TCP bridges at /tmp/claude-http-*.sock and /tmp/claude-socks-*.sock and polls 5× for them to appear. They never do.

What I've tried (no change)

• Full quit + relaunch of Claude Desktop
• Multiple fresh VM boots
• Removing /tmp/claude-* on host
• Confirmed new tasks only, no resume
• Deleted \~/Library/Application Support/Claude/claude-code-vm/\ (forces SDK re-download)
• Deleted \~/Library/Application Support/Claude/vm_bundles/\ (forces full rootfs re-download)

Neither reset changed anything — fails identically after re-download.

Happy to grab further diagnostics if there's something specific you'd like me to run inside the VM.