RACSignal from RACCommand is not subscribed to by `-waitUntilCompleted:`

1

    [[[RACSignal return:@"returnValue"] logAll] waitUntilCompleted:nil];
    NSLog(@"Done waiting for return");
    
    RACCommand *c = [[RACCommand alloc] initWithSignalBlock:^RACSignal *(id _) {
        NSLog(@"Execute command");
        return [RACSignal createSignal:^RACDisposable *(id<RACSubscriber> subscriber) {
            NSLog(@"Command Signal subscribed");
            [subscriber sendNext:@"commandValue"];
            [subscriber sendCompleted];
            return nil;
        }];
    }];
    [[[c execute:nil] logAll] waitUntilCompleted:nil];

    NSLog(@"Done waiting for command");

2-output

2014-08-19 12:41:04.072 RACPlayground[47616:60b] <RACReturnSignal: 0x8f9ed30> name:  next: returnValue
2014-08-19 12:41:04.073 RACPlayground[47616:60b] <RACDynamicSignal: 0x8fbf730> name:  completed
2014-08-19 12:41:04.074 RACPlayground[47616:60b] Done waiting for return
2014-08-19 12:41:04.080 RACPlayground[47616:60b] Execute command