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

Last Action:
2022-01-19 11:01:47,579 [ 43614] INFO - manager.EmulatorProcessHandler - Emulator: /home/ghost/Android/Sdk/emulator/emulator -netdelay none -netspeed full -avd Pixel_API_31
2022-01-19 11:01:47,600 [ 43635] INFO - manager.EmulatorProcessHandler - Emulator: WARNING | unexpected system image feature string, emulator might not function correctly, please try updating the emulator.
2022-01-19 11:01:47,698 [ 43733] INFO - manager.EmulatorProcessHandler - Emulator: WARNING | cannot add library /home/ghost/Android/Sdk/emulator/qemu/linux-x86_64/lib64/vulkan/libvulkan.so: failed
2022-01-19 11:01:47,760 [ 43795] INFO - manager.EmulatorProcessHandler - Emulator: qemu-system-x86_64: -chardev socket,port=45697,host=::1,nowait,nodelay,ipv6,id=modem: address resolution failed for ::1:45697: Name or service not known
2022-01-19 11:02:27,813 [ 83848] INFO - rationStore.ComponentStoreImpl - Saving Project(name=armino_rents, containerState=COMPONENT_CREATED, componentStore=/home/ghost/StudioProjects/armino_rents)KotlinCommonCompilerArguments

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

please run emulator with the following options and post the output here, thanks!
/path/to/emulator -verbose -show-kernel -avd <avename> -feature -ModemSimulator

the above command line will not use modem, just to see if it is related.

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

Yes,it worked.

Attaching the log below.

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

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

I'm getting the same error on my Ryzen 1800X on OpenSUSE Tumbleweed:

"qemu-system-x86_64: -chardev socket,port=38379,host=::1,nowait,nodelay,ipv6,id=modem: address resolution failed for ::1:38379: Name or service not known"

Adding the "-feature -ModemSimulator" flags worked around the issue for me.

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

Hi truefalsetrue101@, could you try look at your /etc/hosts file on your machine? On my machine, it looks like

##
# Host Database
#
# localhost is used to configure the loopback interface
# when the system is booting.  Do not change this entry.
##
127.0.0.1	localhost
255.255.255.255	broadcasthost
::1             localhost

If ::1 localhost is missing, that probably explains why "Name or service was not known".

Issue 171125856