I don't see how this is relevant. Do you want to see Github implement your favorite feature, but at the same time the bugs introduced in the new version breaks

I don't see how this is relevant. Do you want to see Github implement your favorite feature, but at the same time the bugs introduced in the new version breaks the existing functionalities? That's what this library does. It ensures new bugs do not take down existing functionalities. Multi-version execution is an active area of research [1]. [1]: http://srg.doc.ic.ac.uk/files/papers/mx-icse-13.pdf http://srg.doc.ic.ac.uk/files/papers/mx-icse-13.pdf