why RACObserve(self.scoreStepper,value) not available?

[Dast1Woop]

I have the code:
@property(weak) IBOutlet UIStepper *scoreStepper; [[[RACObserve(self.scoreStepper,value) skip:1] take:self.viewModel.maxPointUpdates] subscribeNext:^(id newPoints) { @strongify(self); self.viewModel.points = [newPoints doubleValue]; self.scoreUpdates++; }];
but the code of subscribe cannot be excute.
when I change the code like this:
[[[self.scoreStepper rac_signalForControlEvents:UIControlEventTouchUpInside] take:10] subscribeNext:^(UIStepper * x) { @strongify(self); NSLog(@"value:%f",x.value); self.viewModel.points = x.value; self.scoreUpdates++; }];
it works!
So,I wonder why "RACObserve(self.scoreStepper,value) subscribeNext ..."cannot work?

[ikesyo]

Please open an issue on https://github.com/ReactiveCocoa/ReactiveObjC for the the Objective-C ReactiveCocoa.