I’m getting a File renaming caused colliding pathnames! error from git filter-repo --path-rename (path names hidden due to closed source/confidentiality):

gdlxn@geoff-test4:<git-repo>$ git filter-repo --replace-refs delete-no-add --path-rename <old-path>:<new-path> --force
File renaming caused colliding pathnames!
  Commit: b'd8ab28d76da9371bf1db0dac8870122e57dc6713'
  Filename: b'<new-path>'
fatal: stream ends early
fast-import: dumping crash report to .git/fast_import_crash_415589

My git repository contains a single master branch. I’ve been unable to reproduce the File renaming caused colliding pathnames! error in a small example. So what exactly is meant by colliding pathnames in this context? Any help in understanding the error, and more importantly how to resolve it, would be greatly appreciated.