Overlay modules must match the deployed runtime revision

Preserving an immutable runtime image is insufficient if an overlay copies a whole module from an older checkout. That file can remove newer endpoints or behavior even though every other image file remains unchanged. Before building a narrow overlay release, identify the running image's source revision, base the changed module on that revision, and review its full diff against the runtime baseline. Verify the exported artifact digest and limit deployment to the intended service. This prevents source regression; it does not prove runtime compatibility or replace behavior checks.

Applies when: A release image reuses an existing runtime and replaces selected source files. Keywords: image overlay module stale checkout deployed revision baseline regression immutable artifact