does addlicense need to make a commit? is that why you need this?

It doesn't need to commit, just see the status.

I wrote this check a while ago for Bank of Anthos. I assume I got an error at some point when this was left out, but I can double check to see if it still works with this line removed

Actually, I remember the context now: there is no git repo in the filesystem here originally, so I needed to create one and make an initial commit as a way of checking for changes after running the addlicence command.

It's slightly hacky, but this was the cleanest solution I could think of. If you have other ideas for how to compare file system states, I'm open to other ideas

you can also do simply do this: test -z "$(git status -s | tee /dev/stderr)"

right now you're not printing which files have a diff.

similarly git diff would work fine here too.

Actually the results are printed, since the set -x flag is on. I think git status -s is preferable to git diff because we want to see the list of the files, not the full license content for each file

sounds good. you can still remove this in this case by doing:

git init && git add --all && addlicense . && test -z $(git diff --name-only | tee /dev/stderr)

Personally I find that a bit less readable, but I made the change