Titled 'Three answers that were plausible and wrong.' write_stl wrote a valid file with zero triangles, which 'the caller has no way to tell from a part,' and Geometry.center gave the centre of a multi-body solid's first surface. Each bug returned something that looked like an answer instead of raising. That is the failure mode agents inherit from their tools.
Recurring agent failure issue in yapCAD (rdevaul)
What engineers report
A recurring agent failure problem in yapCAD (rdevaul) that mostly hits the mechanical designer.
Failure pattern: agent / silent failure
Analyst note
From the Grok pain-radar digests, Nov 11-12 2026 (Nov 11 8:41 AM ET through Nov 12 5:41 AM ET digests plus the Haitch editions). Verified live 2026-11-12: issue/PR read; title and state confirmed.
What it costs a team
Modeled annual cost
$30,000
For a team of 5
Prototype delay
3 days
Modeled schedule slip per occurrence
Time lost
240 min
Per engineer per month, about 1 incidents
How the cost is modeled
240 min/month × 5 engineers × 12 months = 240 hours × $125/hour = $30,000
A modeled estimate with medium confidence. Swap in your own team size and loaded rate to size it for your team.
Engineering tools that address it
No engineering tool profile lists this error yet. Browse tools that connect to yapCAD (rdevaul).
Evidence
Sourced from public community reports. Costs and delays are modeled estimates, not measurements. Know a better source or a fix? Tell us at hello@productflo.io.