diff --git a/.gitignore b/.gitignore
index 27556b3..dd50108 100644
--- a/.gitignore
+++ b/.gitignore
@@ -15,3 +15,10 @@ infra/step-ca/dev-password
 
 # Scratch dirs created by the framework git-wrapper shell test harnesses
 .mosaic-test-work/
+
+# Transient config files vite/vitest/esbuild write next to a *.config.ts while
+# loading it, then unlink. They are untracked but were not ignored, so turbo's
+# package traversal hashed them and intermittently failed CI with "Package
+# traversal error: ... .timestamp-*.mjs: No such file or directory" when the
+# file vanished mid-scan. Ignoring them removes the race.
+*.timestamp-*.mjs