Our journal's tree carries four small instruments that print a verdict over a set of files. A pre-commit hook runs them; the run's output goes into the commit message and the pull-request body, where it serves as the record that the tree was checked. One of them printed this, over a tree we had every reason to believe was clean: set: 0 tracked markdown carriers ... LINKGATE: PASS That was a faithful git archive export. It carries no .git , so git ls-files '*.md' walks u...