[Posted in development rather than community in case it is something specific to developer mode and I've included some dev-friendly debug info]
After some cycles of launching an app from my IDE, the Go screen stays on regardless of the sensor state (i.e. on my head or off it) and regardless of whether it is plugged in or not.
When it's working properly I see the following log entries:
...
06-19 13:48:44.620 1375 1375 D VRPowerManagerService: processing message: timer expired
06-19 13:48:44.620 1015 1198 I PowerManagerService: Going to sleep by application request (uid 1000)...
06-19 13:48:44.622 1375 1375 I VRPowerManagerService: transition from HEADSET_UNMOUNTED to WAITING_FOR_SLEEP_MSG
06-19 13:48:44.623 1174 1422 D VrKeyguardService: onStartedGoingToSleep() called with: reason = [2]
06-19 13:48:44.623 1015 1061 I PowerManagerService: Sleeping (uid 1000)...
...
But when it has gone wrong the VRPowerManagerService never seems to fire the timer. Possible suspects include the following log entry I saw at least once when the device had entered a failed state:
06-19 13:34:19.698 1019 1040 E ActivityManager: Sending non-protected broadcast com.oculus.os.libui.app.wakeupdialog.wakeup_dialog_dismissed from system 1355:com.oculus.vrpowermanager/1000 pkg com.oculus.vrpowermanager
06-19 13:34:19.698 1019 1040 E ActivityManager: java.lang.Throwable
06-19 13:34:19.698 1019 1040 E ActivityManager: at com.android.server.am.ActivityManagerService.checkBroadcastFromSystem(ActivityManagerService.java:18072)
06-19 13:34:19.698 1019 1040 E ActivityManager: at com.android.server.am.ActivityManagerService.broadcastIntentLocked(ActivityManagerService.java:18553)
06-19 13:34:19.698 1019 1040 E ActivityManager: at com.android.server.am.ActivityManagerService.broadcastIntent(ActivityManagerService.java:18735)
06-19 13:34:19.698 1019 1040 E ActivityManager: at android.app.ActivityManagerNative.onTransact(ActivityManagerNative.java:499)
06-19 13:34:19.698 1019 1040 E ActivityManager: at com.android.server.am.ActivityManagerService.onTransact(ActivityManagerService.java:2830)
06-19 13:34:19.698 1019 1040 E ActivityManager: at android.os.Binder.execTransact(Binder.java:565)
Happy to provide more info if it would be useful. In case it is relevant, my IDE is Xamarin Studio, my app has a home launcher enabled during development to make debugging easier, and I typically use the volume button to dismiss the Enter VR dialog.