Agent failure was not a Git change
Observed: Apr 2026
An agent workflow stopped working, but recent repository changes did not explain the failure.
- Looked like:
- Code regression
- Actually:
- Outdated toolchain version
Case Notes
Anonymized production debugging notes. Each case shows how the suspected failure boundary moved before the real root cause was found.
Database startup failure was not database configuration
Observed: Nov 2025
A customer-site MySQL service failed to start, and normal database-level checks did not explain the issue.
- Looked like:
- MySQL configuration issue
- Actually:
- Replaced shared library
Intermittent connectivity was not tunnel instability
Observed: May 2026
An edge device appeared unstable through remote access tooling, but the actual failure was inside the local network.
- Looked like:
- VPN / tunnel instability
- Actually:
- LAN IP conflict
Tailscale SSH failure was not node reachability
Observed: Jun 2026
An edge node was reachable over the tailnet, but Tailscale SSH was denied by a separate SSH ACL path.
- Looked like:
- SSH or network reachability failure
- Actually:
- Tailscale SSH ACL mismatch