Note from @mheap: We can now fix this!

We're looking for someone to add a transform that updates the repo to use the $new branch rather than the $old branch as the source for gh-pages. More information in #16 (comment)

Original issue content

Well, I broke a bunch of websites today b/c when you change the name of master to anything else, and its being used by GitHub Pages, it turns off GH Pages & won’t let you turn it back on without some finagling.

So there should probably be some sort of protection for that. Not sure I’ll have time to hack something together myself, but hopefully this serves to warn others.