Resolve Bug

A pipeline, not a single answer. Six phases, two gates, and a verdict that may well be "nothing is broken".

The premise most bug work gets wrong: it assumes a defect exists. Often the system did exactly what it was built to do, and the disagreement is with the product, not with the code. Diagnosing that as a defect produces a fix that breaks correct behaviour.

Language

Answer in the language the request was written in. Findings, explanations, questions, reports and section headings you produce for a developer follow their language — Russian request, Russian answer.