2022.08.10 Rename Git branch from master to main

The only piece of this that shouldn't have been obvious was the idea that the main bare repo on the server had the concept of a checked-out branch and would not delete that branch. I learned that here: https://stackoverflow.com/a/9263023/1128668

Otherwise, this is a fairly simple process.

Steps

Before starting, make sure anyone who might pull from this repo is informed!

DESKTOP$ git --version
git version 2.17.1

Move the branch locally

DESKTOP$ git branch -m master main
DESKTOP$ git status
On branch main
Your branch is up to date with 'origin/master'.

nothing to commit, working tree clean

Push the moved branch to origin

DESKTOP$ git push -u origin main
Total 0 (delta 0), reused 0 (delta 0)
To ssh://server:/opt/git/bareMainRepo.git
 * [new branch]        main -> main
Branch 'main' set up to track remote branch 'main' from 'origin'.

Delete the old branch

DESKTOP$ git push origin --delete master
remote: error: By default, deleting the current branch is denied, because the next
remote: 'git clone' won't result in any file checked out, causing confusion.
remote: 
remote: You can set 'receive.denyDeleteCurrent' configuration variable to
remote: 'warn' or 'ignore' in the remote repository to allow deleting the
remote: current branch, with or without a warning message.
remote: 
remote: To squelch this message, you can set it to 'refuse'.
remote: error: refusing to delete the current branch: refs/heads/master
To ssh://server:/opt/git/bareMainRepo.git
 ! [remote rejected]   master (deletion of the current branch prohibited)
error: failed to push some refs to 'ssh://myname@server:/opt/git/bareMainRepo.git'

Oops. This is where you need to go to the upstream origin server and change which branch is "checked out" in the (presuably) bare repo there

DESKTOP$ ssh server
SERVER$ cd /opt/git/bareMainRepo.git/
SERVER$ git --version
git version 2.17.1
SERVER$ git branch
  main
* master
SERVER$ git checkout main
fatal: this operation must be run in a work tree

Oops. Bare repos don't expect this command. Give it the current directory as a work tree to make it happy

SERVER$ git --work-tree=. checkout main
Switched to branch 'main'
SERVER$ git branch
* main
  master
SERVER$ exit

Done switching the "checked out" branch of the upstream repo. Now go back to the local repo and push a normal branch delete

DESKTOP$ git push origin --delete master
To /opt/git/bareMainRepo.git
 - [deleted]           master

Make sure anyone who might pull from this repo is informed!