Agent's tests passed. Prove they could have failed
Comments on “Agent's tests passed. Prove they could have failed”
3 judges. Scored by all three judges. Only the day’s top stories get the claim check. How far stories are checked
mustfail is an open-source Python tool that checks whether an AI coding agent's passing tests would actually catch its changes. It reverts the agent's source edits to the baseline commit while keeping the new tests, then reruns them; any check that still passes is flagged as undetected.
Why it ranked
No. 90 of 127 with a score of 0.59. The panel rated it highest on new information (0.92) and practical relevance (0.81), lowest on significance (0.41). Placed No. 90, No. 82 by score alone: the 37th AI & machine learning story of the day (−0.080). The placement terms move stories; they are not part of the score.
- AI judgeJudge 2claude-haiku-5-5
- A new open-source tool for verifying coding-agent tests, with a clear mechanism and useful practical value. Self-described early project, limited evidence beyond a small corpus, promotional tone in parts.
- AI judgeJudge 3gpt-5.6-luna
- A technically specific new developer tool addresses a common AI-coding failure mode, with reproducible controls, fixtures, configuration, limitations, and honest caveats. Its evidence is self-reported and detection effectiveness lacks real-world measurements.
Each judge wrote its line after answering the rubric, with the site and the author still hidden. Every answer behind this is in the table under Score.
Score
0.59total under rubric v2.3
- Significance0.41
- Reader interest0.71
- Audience breadth0.54
- Practical relevance0.81
- Substantiated0.72
- Technical depth0.75
- New information0.92
- Counts against: Promotional0.24
- Counts against: Overclaim0.18
Each judge’s answer per question (0–1), their mean and spread, and what the question adds to the score (weight × mean).
| Question | Judge 1 | Judge 2 | Judge 3 | Mean | Spread | Weight | Contribution (weight times mean) |
|---|---|---|---|---|---|---|---|
| SignificanceHow much does this change what people in tech know or can do? | 0.47 | 0.30 | 0.48 | 0.41 | 0.18 | +0.24 | +0.100 |
| Reader interestWould a well-informed senior engineer or tech founder want to read this today, and likely pass it on? | 0.71 | 0.62 | 0.80 | 0.71 | 0.18 | +0.26 | +0.185 |
| Audience breadthHow many people who build technology does it concern? | 0.61 | 0.45 | 0.55 | 0.54 | 0.16 | +0.13 | +0.070 |
| Practical relevanceHow useful is it to someone who builds software or tech products? | 0.86 | 0.75 | 0.82 | 0.81 | 0.11 | +0.22 | +0.178 |
| SubstantiatedHow well is it backed? Consider whether it is the primary source, and whether its main claims come with data, code, a demo, a reproducible method or citations. | 0.88 | 0.50 | 0.78 | 0.72 | 0.38 | +0.05 | +0.036 |
| Technical depthHow technically substantive is it? | 0.93 | 0.60 | 0.72 | 0.75 | 0.33 | +0.05 | +0.038 |
| New informationDoes it contain information absent from the stories covered in the last 7 days (list provided)? | 0.87 | 0.90 | 0.98 | 0.92 | 0.11 | +0.05 | +0.046 |
| PromotionalIs it mainly marketing with little substance (a press release, ad or sponsored post with no real information)? A launch post that carries real news is not promotional. | 0.12 | 0.45 | 0.16 | 0.24 | 0.33 | −0.19 | −0.046 |
| OverclaimDo the headline or conclusions claim more than the body supports? | 0.21 | 0.20 | 0.12 | 0.18 | 0.09 | −0.11 | −0.019 |
| Sum of contributions | +0.586 | ||||||
| Claim-check penalty | 0.000 | ||||||
| Total, as published | 0.586 | ||||||
Spread is the highest minus the lowest judge answer. marks a spread above 0.40: the judges disagree, and the story is marked contested.
The badge for this ranking, for the author's page or anyone's: one line of HTML, and it links back here.
<a href="https://rubric.hrih.si/editions/2026-10-30/90/"><img src="https://rubric.hrih.si/badge/2026-10-30/90.svg" alt="Ranked #90 on Rubric, 30 Oct 2026" width="245" height="28"></a>Also covered by
No other coverage was clustered with this story.
Elsewhere
Elsewhere: HN 1 pts, not on front page
Recorded for context only, checked 30 Oct 2026, 05:47 UTC. It played no part in the ranking.