Sigh, to make the point clearer I use zoltics suggestion and replace the words:
Well, when you test 2.2.1 and report a bug, you hear: it's not relevant anymore, test on 2.3.
But when you try to test on 2.3 and report that you can't test or can't even start. You get to hear: it's developement, it's not supposed to be testable, test stable....
After all it's a game, so every playing is testing and for alomst every testing you need to play.
I know you can't keep it running all the time, but at the moment we have only two states:
The stable, which is too old for testing and the developement version which is constantly broken, sometimes to the point that the compiler complains about the syntax.
Maybe you should simply add a testing branch where you copy the somewhat stable dev version before you start on a modification that is prone to brake the game for a longer time.