It's time to fire up those M preview devices again—Google is in the process of rolling out the second M preview build today. The OTA should arrive on all supported Nexus devices that have the first M build in the next few days. If you're the impatient sort, you can grab the system images right now.
The new M preview has a few notable changes, but it's still a developer preview. Some features (like Now on Tap) won't work until the final release. Here's the changelog from Google.
- Permissions changes
android.permission.USE_FINGERPRINTpermission now has "normal" protection level, so it is no longer necessary to request this permission directly from the user. The
USE_FINGERPRINTpermission enables fingerprints to be enabled for authentication, but does not give the requesting app access to the enrollment/fingerprint administration flow.
android.permission.WRITE_EXTERNAL_STORAGEpermission has protection level "dangerous", meaning that apps wanting to write to external storage will need to request permission from the user at runtime. Both
WRITE_EXTERNAL_STORAGEare members of the
- Remote Bluetooth/Wi-Fi MAC's now require either the
- Some accounts and identity permissions are moved to
CONTACTSpermissions group and others are removed or granted based on account type. In particular,
android.permission.AUTHENTICATE_ACCOUNTSare ungrouped pending further changes in a later release.
- The Wi-Fi permissions
android.permission.CHANGE_WIFI_MULTICAST_STATEnow have protection level "normal".
- The Bluetooth permissions
android.permission.BLUETOOTH_ADMINnow have protection level "normal".
- Bookmarks and subscribed feeds permissions are removed.
- Apps included in the system image are no longer granted dangerous permissions automatically. All apps should check for and request permissions at runtime.
- Introduces the utility method
Activity.shouldShowRequestPermissionRationale(String), which lets your app see whether users have previously rejected a permission request. This lets you know that your app should explain the the user why it needs that permission. For more information see the Permissions developer guide.
- Other changes
android.app.AssistStructureclasses are moved into a new package,
- Bluetooth Stylus APIs are updated and include new callback events. The
View.OnStylusButtonPressListenerclass is renamed to
- TextInputLayout doesn't set hint for embedded EditText. (fixed issue)
- Camera Permission issue with Legacy Apps (fixed issue)
Google has also provided a list of known issues with this build, which you can find below.
- General issues:
- The system Messenger app crashes on the 64-bit emulator.
- After updating to Developer Preview 2, Contacts sync experiences intermittent issues. The workaround is to clear and re-sync Contact Storage data after update. To clear data, go to Settings > Apps > Show system > Contacts Storage. Select "Storage" and then Clear data.
- In YouTube app, it's not possible to share a video. The share window is blank.
- Android For Work Profile setup is not working properly, so you won't be able to create a new Work Profile after you update. As a workaround, make sure to create the Work Profiles you need in Developer Preview 1 before updating to Developer Preview 2.
- Issues specific to MPZ79N on Nexus Player:
- Bluetooth share crashes after clearing data. Please do not clear Bluetooth share data, otherwise you will need to Factory Reset your device
- There are issues with remote control connectivity. Remote can drop from Bluetooth pairing when left idle.
- Movies show black screen with some ANRs on exiting the video.
- In YouTube app, lower-resolution videos have a green bar at the top and some color-ghosting
The updated M preview will have the latest Play Services 7.6 build, and the Nexus player/emulator images have been improved to make validating apps easier.
The Nexus player gets build MPZ79N in this update, but all other devices are MPZ79M. Check the M system image page if you want to manually install it now, otherwise just wait for the OTA. You should get the update on any of the official preview devices that are running the previous build from I/O (MPZ44Q).