Unable to initialize NavBackStackEntry - IllegalStateException: Method addObserver must be called on the main thread [171125856]

Fixed

Bug

Status Update

No update yet.

Description

[Deleted User]

created issue #1

Oct 19, 2020 08:57AM

Component used: Navigation

Version used: 2.2.0, 2.3.0, 2.3.1

Devices/Android versions reproduced on: 10.0, 9.0 - probably not related

Description:

I've updated two dependencies in my project:

androidx.fragment:fragment 1.3.0-alpha06 -> 1.3.0-beta01
androidx.activity.activity 1.1.0 -> 1.2.0-beta01

and now I see that NavController::navigate needs to be called from the main thread. Otherwise NavBackStackEntry throws IllegalStateException when trying to register lifecycle observer.

Stacktrace:

Caused by: java.lang.IllegalStateException: Method addObserver must be called on the main thread
    at androidx.lifecycle.LifecycleRegistry.enforceMainThreadIfNeeded(LifecycleRegistry.java:317)
    at androidx.lifecycle.LifecycleRegistry.addObserver(LifecycleRegistry.java:172)
    at androidx.savedstate.SavedStateRegistryController.performRestore(SavedStateRegistryController.java:61)
    at androidx.navigation.NavBackStackEntry.<init>(NavBackStackEntry.java:84)
    at androidx.navigation.NavBackStackEntry.<init>(NavBackStackEntry.java:69)
    at androidx.navigation.NavController.navigate(NavController.java:970)
    at androidx.navigation.NavController.navigate(NavController.java:867)

There were no changes in documentation so I assume that this behavior is unintended.

Comments

il...@google.com <il...@google.com> #2Oct 19, 2020 08:10PM

Indexing also runs indefinitely here with Android studio 3.3 and a project that contains a NDK library (native engine + game). Previous versions, for instance 3.2.1, worked fine. Still occurs after clearing the caches and deleting the .idea folder. On a desktop with 32 GB of RAM it's not running out of memory but it indexes forever, pegging an entire CPU and disk access to 100%, and it never stops. The same thing occurs with gradle 4.6 or 4.10. If I enable the experimental scan active configuration only setting, everything is basically broken - no syntax highlighting, cpp files don't show. Waiting to see if there's a workaround before reverting to 3.2.1 and being much more cautious about updating in the future ..

[Deleted User] <[Deleted User]> #3Oct 20, 2020 07:19AM

When I let it run for hours, the scanning eventually did complete, then the indexing took more hours, I let it run as well, and eventually it switched to 'building symbols' which also started taking a long time without progress, but that, eventually, crashed Android Studio with an out of memory error, telling me to increase the heap size. I did, and upon restarting Android Studio, it started over at scanning .. so I gave up for now. This is with a mid-size NDK project.

ap...@google.com <ap...@google.com> #4Apr 6, 2021 10:13PM

Even after a dirty downgrade to AS 3.2 from 3.3 my project was stuck on scanning files to index and building symbols. I ended up having to fully remove all Android Studio files/folders. After relaunching AS 3.2 and setting heap size to 8GB the scanning, indexing and building symbols took just a couple minutes.

il...@google.com <il...@google.com> #5Apr 6, 2021 10:17PM

Marked as fixed, reassigned to il...@google.com.

These were the folders I deleted:
rm -rfv ~/Library/Application\ Support/AndroidStudio*
rm -rfv ~/Library/Preferences/AndroidStudio*
rm -rfv ~/Library/Caches/AndroidStudio*
rm -rfv ~/Library/Logs/AndroidStudio*
rm -rfv ~/.AndroidStudio*

ap...@google.com <ap...@google.com> #6Apr 12, 2021 11:58PM

Any chance someone has a repro project they can share?
@brigham, are you saying deleting those folders help with your issue?

Issue 171125856