Tip: Assign an Agent a Dedicated 'Find the Release Blockers' Pass Before a Major Version Bump

Simon Willison·medium signal

In the sqlite-utils 4.0 work, Claude Fable surfaced 5 issues categorized as release blockers that Simon Willison hadn't encountered himself — including a silent transaction bug — across a focused review of a backwards-compatibility-sensitive major bump. The reusable technique: before cutting a breaking release, run a single agent task scoped only to 'enumerate everything that could break existing callers,' separate from feature work. It exploits the agent's willingness to exhaustively trace edge cases a human maintainer skims past.