Hi , we are getting this crash: `Fatal Exception: ...

# compose

[vicky7230]

Hi , we are getting this crash:
Fatal Exception: java.lang.IllegalArgumentException: No destination with route landing is on the NavController's back stack. The current destination is Destination(0x41295e74) route=neo_activation/{neoLaunchModeArg}/{neoTripIdArg}
at androidx.navigation.NavController.getBackStackEntry(NavController.kt:2230)
This is the code:

fun NavGraphBuilder.neoBookingScreen(navController: NavController, onBackClick: () -> Unit) {
    composable(route = neoBookingRoute) { entry ->
        val neoViewModel: NeoViewModel = entry.sharedViewModel(navController)

        NeoBookingScreenRoute(neoViewModel = neoViewModel, onBack = onBackClick)
    }
}

@Composable
inline fun <reified T : ViewModel> NavBackStackEntry.sharedViewModel(
    navController: NavController
): T {
    val navGraphRoute = destination.parent?.route ?: return hiltViewModel()
    val pareEntry = remember(this) { navController.getBackStackEntry("landing") }
    return hiltViewModel(pareEntry)
}

I am not able to find the root cause here. we are using androidx.navigation:navigation-compose 2.5.3 here

[vicky7230]

cc: @Ian Lake

[vicky7230]

why thumbs down?

[Jack Boswell]

Why would you tag Ian in this?

[vicky7230]

I saw a few cases where ian answered:
1. https://stackoverflow.com/questions/78776233/error-when-using-popbackstack-no-destination-with-route-is-on-the-navcontrolle#:~:text=1 Answer&text=0-,remember(navController.,been%20popped%20off%20the%20graph.&text=Sign%20up%20to%20request%20clarification%20or%20add%20additional%20context%20in%20comments.
2. https://slack-chats.kotlinlang.org/api/link/1a905bbc-fd5b-42c7-9683-c8824ba05d78/506061

[Jack Boswell]

Anyways, the root cause is that there is no destination with the route landing in your backstack, so when you call getBackStackEntry looking for route landing it throws an exception

[Jack Boswell]

I don't think we can tell you why landing isn't in your backstack based on the code you shared, that'd be something worth looking into

[vicky7230]

we looked at the crash yesterday, tried to find the root cause but we were not, hence asked here

[vicky7230]

Even though it is clear that there is no destination with the route landing in backstack, but it is not possible to navigate to the neo_activation screen without landing .

[vicky7230]

The links I shared above are pointing to some what same issue.

[Jack Boswell]

The issue you linked points out using the incorrect backstack handle - I don't think that's your issue, since you aren't interacting with the current backstack entry directly

[Jack Boswell]

Again, I can't tell you why your landing route isn't on the backstack based on the code you shared, but it's a fact that it's not there

[Jack Boswell]

That could be because landing is a route on a different nav controller, or because it was popped from the backstack when navigating, or maybe it was never there to start with. There's not enough information in your post to narrow it down

[Jack Boswell]

It might be helpful for you to put a breakpoint or log whenever your backstack changes so that you know what gets added and removed when

[Chrimaeon]

@vicky7230 for next time and because you where curious about the 👎🏻

• Please do not ping or mention someone directly to get your questions answered, especially project owners, whether the project is Kotlin or other, unless they specifically indicate that you can.

https://kotlinlang.org/docs/slack-code-of-conduct.html#basic-usage-guidelines

[vicky7230]

NOTED