Move master branch to main

[jennybc]

Cc @jennybc

The master branch of this repository will soon be renamed to main, as part of a coordinated change across several GitHub organizations (including, but not limited to: tidyverse, r-lib, tidymodels, and sol-eng). We anticipate this will happen by the end of September 2021.

That will be preceded by a release of the usethis package, which will gain some functionality around detecting and adapting to a renamed default branch. There will also be a blog post at the time of this master --> main change.

The purpose of this issue is to:

• Help us firm up the list of targetted repositories
• Make sure all maintainers are aware of what's coming
• Give us an issue to close when the job is done
• Give us a place to put advice for collaborators re: how to adapt

message id: entire_lizard

[jennybc]

GitHub's support for default branch renaming means that, in general, pull requests that target the default branch will be correctly re-targetted.

However, there are some edge cases, where this is not true. Some pull requests are automatically closed when the default branch is renamed and they cannot be re-opened. This happens when the PR-making branch, fork, or user no longer exists. (Literally, it appears to boil down to whether HEAD of the PR branch is available for whatever behind-the-scenes magic is happening.)

There are 2 open pull requests in this repo that are at risk of auto-closing:

#242 and #241

A way to "rescue" the work on such a PR is described in isaacs/github#168 (comment). Here's the TL;DR:

If there is a PR displaying unknown repository after the fork was deleted, and you want to resurrect that PR, simply type:

git fetch origin refs/pull/123/head:foo

substituting (if necessary) origin for the remote pointing at the target repo, 123 for the PR number, and foo for the name of the local branch you want created to point to the head of the PR.

Then you can simply git checkout foo ... and resubmit a new one ....

message id: hardhearted_newt

[jennybc]

This repo was selected for an early switch from master to main, to help refine our process for the larger effort. Thank you for your service!

When we scale this up to all ~350 repos, there will be a public announcement pointing to a blog post about this change, pointing out the usethis functions available to package maintainers and contributors to support default branch renaming.

In the meantime, this blog post is available in draft form and can be read here.

message id: exalted_aphid