From 2d32592d235d15473705411286f2e710dcc9e3d1 Mon Sep 17 00:00:00 2001
From: Frank O'Hara <frankj.ohara@gmail.com>
Date: Thu, 27 Aug 2026 07:41:35 -0600
Subject: [PATCH] docs: note fork-PR behavior of the mutation check

---
 CONTRIBUTING.md | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/CONTRIBUTING.md b/CONTRIBUTING.md
index acfbf80..58c5cfc 100644
--- a/CONTRIBUTING.md
+++ b/CONTRIBUTING.md
@@ -881,3 +881,5 @@ Contributors will be recognized in:
 - Mentioned in release notes (for significant contributions)
 
 Thank you for contributing to Lash!
+
+Note: the mutation-testing check does not run on fork PRs (repository secrets are unavailable to them); a maintainer pushing the branch to the main repo exercises it.