I've forked a repo that has gh-pages set as it's default branch. They're hosting it on a custom domain, so there is a custom CNAME file.
I'm getting emails from Github with the following:
The page build completed successfully, but returned the following warning:
CNAME already taken: styleguides.io
I don't need to host the site myself, the fork is just for making contribs back. I'm just looking for a way to disable gh-pages hosting for my fork, so I don't get these errors/emails anymore.
I would suggest renaming the "branch" in your fork to something other than gh-pages, that should prevent it from triggering builds, but will still allow you to pull request to the gh-pages on the upstream parent.
Switch to the gh-pages branch on that forked repo. Then remove the CNAME file. That should fix this problem.
You can get those emails because your forked repo tried to send the GitHub server the same CNAME settings as another project. (In your case, the upstream repo you forked from.)
来源：https://stackoverflow.com/questions/27302712/can-i-disable-gh-pages-hosting-for-my-forked-repo