Google-search – How to do a Google search about GitHub without getting results from public repositories

githubgoogle-search

I tried to search a private code base on GitHub for a string that included a [^*. It gave me a pretty 500 error page so I jumped over to Google and searched for "github search special characters". Almost all of the results came back as links to issues from public repositories relating to special characters breaking search in their code.

How can I exclude results from public GitHub repositories?

I thought about restricting the search to help.github.com but that would exclude any results external to GitHub such as blog posts.

^{* I can search issues with strings that include square brackets, but not code.}