diff -c cps/templates/remote_login.html ../calibre-web/cps/templates/remote_login.html > remote_login.patch

Build the image on macOS with orbstack docker:

docker build . --platform linux/amd64  --debug

docker build . --no-cache --load --platform linux/amd64  2>&1 | tee build.log 

diff -Naur <original_file> <new_file> > <patch_filename>.patch