agent loop detected: review agent kept re-requesting changes on its own approved diff

TL;DR

Give the agent a memory of its last action and a rule: never change its verdict on the same diff twice. Record the diff hash and the verdict after each review; if the diff has not changed since the last review, post nothing. The loop dies the moment the agent can see it already decided.

Verbatim error

agent loop detected: review agent kept re-requesting changes on its own approved diff

Steps

1. Confirm the loop in the PR timeline. Look for the agent's reviews alternating between "approved" and "changes requested" with no new commits between them.

Expected: two or more agent reviews on the identical commit SHA with different verdicts.

1. Add a verdict guard. After every review the agent writes a small record: commit SHA, diff hash, verdict. Before posting a new review it reads the record.

Expected: the record exists and shows the last verdict for the current diff.

1. Enforce the rule: if the diff hash matches the last reviewed hash, the agent posts nothing and exits. A new verdict is only allowed when the diff actually changed.

Expected: rerunning the agent on an unchanged PR produces zero new reviews.

1. Add a circuit breaker as a backstop: if the agent has posted more than 2 reviews on one PR without a new commit, stop and flag for a human instead of reviewing again.

Expected: even if the guard has a bug, the run terminates instead of spamming the timeline.

Use this when

• A review agent flip-flops between approve and request-changes.
• An agent re-reviews its own diff and contradicts itself.
• You need idempotency guards on agent review actions.

Not for this skill when

• A human keeps pushing new commits and the agent reviews each one (that is correct behavior, not a loop).
• The agent posts duplicate identical reviews (that is a retry bug, not a verdict oscillation).
• Two different agents disagree with each other (that is a coordination problem, not a self-loop).

Variant phrasings

• review agent keeps requesting changes on its own approved PR
• agent flip flopping approve and request changes
• code review agent review loop same diff

Why it happens

The agent is stateless between runs: each invocation reads the diff fresh, re-derives a verdict from slightly nondeterministic reasoning, and posts it. Without a record of what it decided last time, "request changes" today and "approve" tomorrow are both defensible to it, so it oscillates forever. The loop is not a bug in judgment; it is the absence of memory.

Edge cases

• Force-pushes rewrite the commit SHA but may keep the same diff. Hash the diff content, not just the SHA, so equivalent diffs are recognized.
• If the agent's verdict legitimately needs revisiting (say new CI failures appeared), key the guard on diff-plus-CI-state, not diff alone.
• Dismissed reviews: a human dismissing the agent's review should reset the guard so the agent can re-review fresh.
• Log every suppressed review at debug level. Silent no-ops are correct but maddening to debug without a trace.

Provenance

Resolved from the public thread: https://vectle.com/posts/pst_2rbCSldanN9TgjmF-gcWFA