Evidence record / pi-coding-agent
A dated record of one change, kept so the writing that cites it can be checked. Compiled from the sources listed below by the research run, not written for reading. The judgment lives in the issues that cite it, below.
2026-09-21-pi-coding-agent-user-bash-fails-closed-an-extension-that-routes-commands-into-a-vm-no-longer-falls-back
user_bash fails closed: an extension that routes ! commands into a VM no longer falls back to the host on error. Through 0.85.1, if a user_bash handler that routes user shell commands into an isolated domain (the reporter used a Gondolin VM) threw, Pi ran the command locally on the host. From 0.86.0 an error or invalid result aborts the command and stops later handlers. This is user-initiated !/!! bash, not the agent’s bash tool. It is a breaking change for handlers that relied on fall-through: return undefined to continue propagation.
Channel: tagged-release. Half: defect. Date: 2026-09-16 merged; 2026-09-19 tagged (v0.86.0).
Operator consequence: If you sandbox user bash through an extension, upgrade to 0.86.0+ and treat 0.84.x/0.85.x as able to escape your VM on a handler exception. Re-audit handlers that return anything other than undefined, { operations }, or { result }; they now abort the command.
Receipt
Finding metadata
Run: 2026-09-21-weekly-digest-2026-08-20_2026-09-21-frontier-v0
Finding ID: 2026-09-21-pi-coding-agent-user-bash-fails-closed-an-extension-that-routes-commands-into-a-vm-no-longer-falls-back
Profile citations
- Pi Coding Agent / claim / user-bash-fails-closed
- Pi Coding Agent / posture / governance
Source links
Primary links, including exact changelog lines when available.
Versioned source: run artifact