Mole bug patterns

Use this project-specific catalog after reading the current diff and code. Generic pattern sweeps belong to Waza check Pattern-Fix Completeness; root-causing a live symptom belongs to hunt.

Load only the archetypes signaled by the symptom or touched surface, then use their probes to sweep siblings. A whole-project audit should classify surfaces before opening sections instead of treating all twelve as a mandatory checklist. Read references/shell-and-test-pitfalls.md only for Shell code, Bats tests, install/update flows, timeout wrappers, TTY handling, plist fixtures, or macOS-specific CI.

How to use the catalog

• Sweep siblings without waiting for another report. One instance of a recurring shape is evidence to inspect every same-shape call site.

• A fix ships with a guard. Add a regression or source-invariant test that fails on the pre-fix code. Inspect current history only when a numerical trend matters to the decision.

• The dominant defect is not a crash. It is a path deleted on weak evidence, a number that disagrees with another number computed elsewhere, or a scan that looks hung while it is merely unbounded. Nothing throws. So the productive question is never "can this crash", it is:

  What does this produce when the probe is denied, the app is installed in a place the probe does not look, the machine is slow but healthy, or the cache was written by the previous release?

The twelve archetypes

Ranked by how often they recur. Walk the ones the area touches and write down present / absent / unsure for each. "Absent" is a result worth reporting.