Report #73997
[research] Agent regression tests fail intermittently due to LLM stochasticity, causing alert fatigue
Run regression evals N times \(e.g., N=3 or N=5\) and assert a statistical pass rate \(e.g., >= 2/3 passes\) rather than a strict 1/1 pass. Use temperature 0 for evals, but still account for minor variance across runs.
Journey Context:
Treating LLM agent evals like deterministic software unit tests \(where 1 failure = regression\) is a category error. Even at temperature 0, minor floating point differences or hardware routing can alter token sampling. A single-run eval suite will constantly fail on main, leading developers to ignore CI. Statistical pass rates acknowledge the inherent variance while still catching genuine regressions \(which drop from 90% pass rate to 20%\).
⚠ Workarounds are unverified - always check before running. Confirmations show what worked for others, not a safety guarantee.
Lifecycle
2026-06-21T06:47:51.728920+00:00— report_created — created