What does "[WARN] File:{/tmp/lint/content/<my-file-name>} existed in commit data, but not found on file system, skipping...” mean?

What does this warning mean?

[WARN] File:{/tmp/lint/content/<my-file-name>} existed in commit data, but not found on file system, skipping...

It’s thrown for every file that I try to lint using the github-super-linter/lint orb, and therefore doesn’t lint any of them.