IssueTracker

Can you include a sample project that reproduces your issue?

Note that if you want to just return to your main graph (which I assume launched your login_nav_graph), you would want to leave out the app:destination="@id/main_nav_graph" line entirely as that will create a second instance of your main_nav_graph.

Thank you! While working on a minimal repro and keeping your comment in mind, I solved my problem.

My problem was partly that I had an app:destination in my pop action, but also that the action leading to login_nav_graph was popping:

<action
    android:id="@+id/logout"
    app:destination="@id/login_nav_graph"
    app:popUpTo="@id/main_nav_graph"
    app:popUpToInclusive="true" />

Here is a working sample of what I wanted to achieve:

main_nav_graph.xml

<?xml version="1.0" encoding="utf-8"?>
<navigation xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:id="@+id/main_nav_graph"
    app:startDestination="@id/mainFragment">

    <fragment
        android:id="@+id/mainFragment"
        android:name="app.reitan.navigationrepro.MainFragment"
        android:label="fragment_main"
        tools:layout="@layout/fragment_main">
        <action
            android:id="@+id/to_login_nav_graph"
            app:destination="@id/login_nav_graph"/>
    </fragment>

    <include app:graph="@navigation/login_nav_graph" />
</navigation>

login_nav_graph.xml

<?xml version="1.0" encoding="utf-8"?>
<navigation xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:id="@+id/login_nav_graph"
    app:startDestination="@id/loginFragment">

    <fragment
        android:id="@+id/loginFragment"
        android:name="app.reitan.navigationrepro.LoginFragment"
        android:label="fragment_login"
        tools:layout="@layout/fragment_login">
        <action
            android:id="@+id/pop_login_nav_graph"
            app:popUpTo="@id/main_nav_graph"
            app:popUpToInclusive="true" />
    </fragment>
</navigation>

Even though the error was probably in my code, this is still a change of behavior, as this used to work fine in 2.3.0. Just so you know :)

Trying to recreate this issue in a sample project as well, but I am seeing the same thing. However I am navigating by id instead of action.

While the project in comment#6 is absolutely the wrong way to do conditional navigation (instead, you should follow the guide for login, it does reproduce the issue reliably enough for us to pinpoint what the problem is.

We've fixed the underlying issue (related to popping the root graph, then navigating to another nested graph) internally and it will be available in Navigation 2.4.0-alpha03.