Okay, Git 2.30 doesn't really change "master" to "main", but it prints a
big yellow deprecation warning:

    $ git init
    hint: Using 'master' as the name for the initial branch. This default branch name
    hint: is subject to change. To configure the initial branch name to use in all
    hint: of your new repositories, which will suppress this warning, call:
    hint: 
    hint: 	git config --global init.defaultBranch <name>
    hint: 
    hint: Names commonly chosen instead of 'master' are 'main', 'trunk' and
    hint: 'development'. The just-created branch can be renamed via this command:
    hint: 
    hint: 	git branch -m <name>

This is probably the best they can do in terms of a migration path. It
works well for people who use Git on the command line. People using Git
in IDEs, I don't know ... They might miss it. But what other options are
there? Error out and *force* people to configure a default branch name?
Hmmm.