Thunderbird pack hook $HOME resolved to /root, breaking email injection for all Horizon jobs
| Date | 2026-03-25 |
| Severity | SEV-2 (est.) |
| Prod breaker | Will |
| Status | Resolved |
Summary
The Thunderbird pack hook was changed from the hardcoded path /home/model to
$HOME. The hook runs as root, so $HOME resolved to /root — email
injection silently landed in the wrong home directory and broke all Horizon
jobs that depended on it.
Lesson: environment variables lie under privilege changes; pin absolute paths in hooks that run as root.
Backfilled from the days-since-prod-break dashboard — this predates the incident log, so no full postmortem exists.