diagnose-before-fix
Bucket: discipline · Invocation: automatic
Finds a supported cause for a reproducible technical failure before committing a production fix.
Use the narrowest reliable reproduction as ground truth. Reduce the failure, trace the nearest seam, compare plausible causes, and run high-information checks. Tests, logs, and temporary instrumentation inside the task scope are available working surfaces.
Once evidence supports a cause, implement the smallest fix and rerun the original failing path. When the cause cannot be distinguished, report bounded uncertainty and the next useful check rather than presenting a hypothesis as a diagnosis.
Transcript: no reproducible system
Trimmed from trigger case DBF-P1 on 2026-07-30.
text
User:
"Login started returning 500 after the last change. Find why and fix the cause."
diagnose-before-fix:
"Reproduce before proposing a production patch."
Command: rg --files
Exit: 0
Result: README.md and AGENTS.md only.
Command: git status --short
Exit: 1
Result: not a Git repository.
Agent:
"The cause cannot be established here. I need the application code and
the 500 stack trace or the last diff; otherwise a fix would be guesswork."