Coding agent CLI Linux sandbox fails with "mountinfo path is not absolute" after an update

After a Desktop or VS Code extension update that bundled CLI 0.155.0-alpha.16, every sandboxed command and patch fails while the Bubblewrap command is being built. System bwrap still works.

Difficulty

Moderate

Time

~15 min

Steps

Fixed in

—

Last checked

2026-10-15

Unverified: we could not confirm from the sources that a fix shipped. Source: issue closed as completed, no linked fix. Last checked 2026-10-15.

Symptom

After a Desktop or VS Code extension update that bundled CLI 0.155.0-alpha.16, every sandboxed command and patch fails while the Bubblewrap command is being built. System bwrap still works.

Evidence what you'll see

Error: error building bubblewrap command: mountinfo path is not absolute
Hosts with snapd namespace mounts were most likely to hit it
codex sandbox /bin/true fails

Cause

A staff comment called it a known Linux sandbox bug with namespace mounts such as snapd's, and said newer CLI builds handle it while the affected packages bundled the older alpha.

Fix steps

0 of 4 done

Step 1Update the coding agent Desktop app or the VS Code extension. A user reported extension 26.928.31416 working again.
Step 2While stuck on the affected bundle: point the extension setting chatgpt.cliExecutable (or the environment variable CODEX_CLI_PATH for Desktop) at a standalone CLI 0.156.0 or newer.
Step 3VS Code only: roll back to extension 26.908.40401.
Step 4A related WSL error (app-server socket directory has an unsupported host mount at /mnt/wslg/distro): set guiApplications=false under [wsl2] in .wslconfig, then wsl --shutdown.

Your check marks stay in this browser only.

Verify the fix worked

codex sandbox /bin/true exits 0.
A sandboxed shell command and a small patch succeed in a session.

Did this fix it?

Sources and credit

Summarized in our own words from these public reports. Credit goes to their authors.

Provided as is, without warranty. Test in a non-production environment and back up first. Security-related steps: verify against the official docs. Terms · Request removal or attribution change