If you fork and add a github pipeline such as: 

https://github.com/i386/app-store-demo

And open a branch that is something like "foo/bar", edit the pipeline, when you save it you will see: 

However, it did actually save to github, but it wasn't able to find the pipeline to trigger a scan/build for and then redirect to. This must be one of those encoding problems

For other branch names, it works as advertised.