Luca replied. We can compile current binaries. It seems Make still works fine on these branches. Great. I can now fly all my uBrains again.
Reply from Luca follows:
We have a branch for Copter 3.5.5 here
To build for vrbrain you have to use make (make vrubrain-v51 or vrubrain-v52)
The last stable is Plane-3.8.4 but today I have created Plane-3.8.5 also!