There's no circumstance where a .DS_Store file, on macOS, should ever be in a git repository. Unfortunately, many don't put it in their .gitignore, with the result that it gets preserved. I recommend ...
Mac's Finder (file browser) automatically adds .DS_Store files to browsed folders. So there may be a .DS_Store file in the folder that dustmite is going to run on. dustmite then errors with: ...