Debugging

Find the cause first. A fix without one is a guess that moves the symptom.

1. Reproduce it. Get the exact input, command and output. If it won't reproduce, say so and stop guessing.
2. Read the evidence. The full error, the stack, the log lines around it, and git log for what changed lately.
3. Narrow it. Compare a working case with the broken one. Bisect by commit, input or code path, and change one thing at a time.
4. Say the cause in one sentence and the check that shows it: "X fails because Y; Z proves it." Run the check.
5. Fix that cause, with the test that would have caught it (see bud:code-style).
6. Show the same reproduction passing (see bud:verify).

If three fixes in a row haven't worked, the cause is wrong. Go back to step 2 and tell Jason what you ruled out.