Isn't https://github.com/libgit2/php-git what you're looking for?

you're certainly aware that libgit2 is a reimplementation of git, largely sponsored by github since the original git libraries are binding-unfriendly to say the least. The de-facto ruby "bindings" (grit) were a mere wrapper around cli git and afaik this used to be the only way to go.

I tried to use libgit2 for a project last year and a coworker did a couple of patches and I can say that there's still a lot of ground to cover until libgit2 is at least somewhat feature complete. Back then, clone via SSH and other _must_have_ features were unimplemented.

Linus uses libgit2 [0] albeit as a data format, not as a basis for VCS.

[0] https://plus.google.com/+LinusTorvalds/posts/X2XVf9Q7MfV

How unlucky, you must have just missed it. Clone via ssh was added in May last year!

What were the other must-haves that were missing?

And surprise! I did not argue that. I wish people would read my comment a bit more carefully.

You said:

"If any SVN dev truly believes that svn is better than git in any technical sense then I wouldn't trust the engineering judgment of that developer."

and I gave one example in which svn 'is better than git in a technical sense'.

Poor choice of words on my part, but when I said "in a technical sense", I meant it's data model and architecture. Bindings are just a feature that can be written at any time, data model and architecture are something that can never be fixed.

More importantly, I specifically alluded to use cases that svn is better than git for. In no way did I ever "argue that there is no single use case which wouldn't be affected by this".