I had an active branch (not pushed to github) while I changed the default branch and experienced no issues when I submitted the pull request after I completed the conversion to main.
That said, once my local environment was converted to main, I rebased my active branch with main before pushing it up. But even if I had a PR up before the conversion I should have been able to change the branch target in the github ui.
Let me know if you run into any issues and I'd be happy to help debug the issues!
I think I got it. git rebase --onto main just rewound the HEAD revision, but then GitHub Desktop told me I had commits to push and pull; once I did that, everything looks peachy. (Maybe leaving out --onto would have made it one step...)
git rebase --onto main
Now, once GitHub changes GitHub Pages to work from the default branch (which I imagine has to be something they'll do soon, since they're all in on this), I can completely remove it.
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