# PR#107: A Weakened Merge Gate Waits for the Human

> **WARNING:** This document describes only the change applied in this PR.
> It may already be outdated once the next PR is merged.
> Historic PR documentation is not maintained along with new PRs; treat it as a snapshot.

## Related Links

- [PR#106](2026-10-14-PR#106-codex-gate-severe-test.md): the severe gate test that werkrevisor did not see.
- [PR#46](2026-10-08-PR#46-risk-categories.md): the risk categories.

## Problem

In PR#106 a defect let the approval of the bot count as a human approval for the Codex gate.
werkrevisor saw the change, but rated it GREEN-worthy:
Jev rated `weakens_checks` 0.18 and `security` 0.66 for `werkrevisor/codexrunner.py`.
werkrevisor is the merge gate of all werk repositories, so a change that weakens it must wait for the human.

## Non-Goals

- No change of the code; the category is configuration of this repository.
- No ORANGE: four weakened gates are too few to calibrate `orange_min`.
- Werkator gets its own category in its repository; see Follow-up PRs.

## Specification

### Feature: a weakened merge gate waits for the human

#### Scenario#107.01: Jev rates a weakened gate as likely

So that a change that lets PRs merge with less review never merges without the human.

- **Given** the configuration of werkrevisor
- **When** Jev rates a main-code file at 0.75 or more for `gate_weakened`
- **Then** the review is YELLOW with the reason `risk_gate_weakened`

##### Verified by

- [test_risk: test_werkrevisor_holds_a_weakened_gate_for_the_human](../../tests/test_risk.py)

#### Scenario#107.02: a gate change below the threshold passes

So that the usual changes of the review, which all touch the gate, need no human.

- **Given** the configuration of werkrevisor
- **When** Jev rates a main-code file below 0.75 for `gate_weakened`
- **Then** the category gives no YELLOW

##### Verified by

- [test_risk: test_werkrevisor_holds_a_weakened_gate_for_the_human](../../tests/test_risk.py)

## Solution

- `.werkrevisor.toml`: a category `gate_weakened` of its own, for main code, `action = "yellow"`, `yellow_min = 0.75`.
- Version 0.42.0.

## Measurement

On 2026-10-14 Jev judged each changed main-code file of the 22 merged PRs #85 to #106,
the defects of PR#105 and PR#106, and three weakenings made for the measurement.
Two questions were compared:
`merge_gate` asked whether the change alters who or what may approve, hold or release a merge;
`gate_weakened` asked whether it makes it easier to merge without the required review.

| Case | `merge_gate` | `gate_weakened` |
|---|---|---|
| PR#106 defect: the bot approval counts | 0.91 | 0.84 |
| `hints_hold_merge` defaults to false | 0.95 | 0.82 |
| an approval before the result counts | 0.90 | 0.88 |
| a failed Codex review gives `success` | 0.91 | 0.89 |
| highest of the 22 merged PRs | 0.91 (PR#94) | 0.68 (PR#98, a diagram generator) |
| PR#105 defect: one review more per run | 0.87 | 0.56 |

`merge_gate` rates most feature PRs of werkrevisor high, since werkrevisor is the gate.
`gate_weakened` separates: the four weakenings from 0.82 on, the merged PRs at most 0.68.
0.75 lies between both; two runs differed by about 0.02.
The measurement cost less than 0.01 USD.

## Open Questions

None.

## Follow-up PRs

- [werkator PR#159](https://git.javagil.de/mi/werkator/pulls/159): Werkator gets the category `status_misreported`
  and a hard path, since `gate_weakened` rated its weakened statuses at most 0.46.