Github deploy.sh not working?

I followed the instructions on Hosting On Github page, but after running it once, it stops working.

After making any changes to a post and running ./deploy.sh I get nothing to commit, working tree clean. I guess Hugo is not building again because I already have the public folder. But, if the folder is a submodule, I can’t delete it, as that would require re-adding the submodule again. Is the github deploy script wrong?