$ vi .git/hooks/pre-commit
$ chmod +x .git/hooks/pre-commit
$ git add .git/hooks/pre-commit
$ git status
On branch master
Your branch is up to date with 'origin/master'.
nothing to commit, working tree clean
あれれ?
> It’s important to note that client-side hooks are not copied when you clone a repository.
https://git-scm.com/book/en/v2/Customizing-Git-Git-Hooks
そうだったんだ