IssueTracker

Here is the stacktrace from the provided sample project

```    --------- beginning of crash
2018-05-16 13:39:54.438 29258-29258/? E/AndroidRuntime: FATAL EXCEPTION: main
    Process: io.kayvan.io18spike, PID: 29258
    java.lang.RuntimeException: Unable to start activity ComponentInfo{io.kayvan.io18spike/io.kayvan.io18spike.MainActivity}: android.view.InflateException: Binary XML file line #10: Binary XML file line #10: Error inflating class fragment
        at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2925)
        at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:3060)
        at android.app.servertransaction.LaunchActivityItem.execute(LaunchActivityItem.java:78)
        at android.app.servertransaction.TransactionExecutor.executeCallbacks(TransactionExecutor.java:110)
        at android.app.servertransaction.TransactionExecutor.execute(TransactionExecutor.java:70)
        at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1800)
        at android.os.Handler.dispatchMessage(Handler.java:106)
        at android.os.Looper.loop(Looper.java:164)
        at android.app.ActivityThread.main(ActivityThread.java:6649)
        at java.lang.reflect.Method.invoke(Native Method)
        at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:493)
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:826)
     Caused by: android.view.InflateException: Binary XML file line #10: Binary XML file line #10: Error inflating class fragment
     Caused by: android.view.InflateException: Binary XML file line #10: Error inflating class fragment
     Caused by: java.lang.RuntimeException: Exception inflating io.kayvan.io18spike:navigation/nav_graph line 12
        at androidx.navigation.i.a(Unknown Source:124)
        at androidx.navigation.d.a(Unknown Source:4)
        at androidx.navigation.fragment.NavHostFragment.f(Unknown Source:88)
        at android.support.v4.app.h.k(Unknown Source:15)
        at android.support.v4.app.n.a(Unknown Source:367)
        at android.support.v4.app.n.b(Unknown Source:7)
        at android.support.v4.app.n.a(Unknown Source:74)
        at android.support.v4.app.n.onCreateView(Unknown Source:216)
        at android.support.v4.app.k.a(Unknown Source:4)
        at android.support.v4.app.i.a(Unknown Source:2)
        at android.support.v4.app.e.onCreateView(Unknown Source:0)
        at android.support.v4.app.i.onCreateView(Unknown Source:0)
        at android.view.LayoutInflater.createViewFromTag(LayoutInflater.java:780)
        at android.view.LayoutInflater.createViewFromTag(LayoutInflater.java:730)
        at android.view.LayoutInflater.rInflate(LayoutInflater.java:863)
        at android.view.LayoutInflater.rInflateChildren(LayoutInflater.java:824)
        at android.view.LayoutInflater.inflate(LayoutInflater.java:515)
        at android.view.LayoutInflater.inflate(LayoutInflater.java:423)
        at android.view.LayoutInflater.inflate(LayoutInflater.java:374)
        at android.support.v7.app.j.b(Unknown Source:23)
        at android.support.v7.app.c.setContentView(Unknown Source:4)
        at io.kayvan.io18spike.MainActivity.onCreate(Unknown Source:6)
        at android.app.Activity.performCreate(Activity.java:7130)
        at android.app.Activity.performCreate(Activity.java:7121)
        at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1262)
        at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2905)
        at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:3060)
        at android.app.servertransaction.LaunchActivityItem.execute(LaunchActivityItem.java:78)
        at android.app.servertransaction.TransactionExecutor.executeCallbacks(TransactionExecutor.java:110)
        at android.app.servertransaction.TransactionExecutor.execute(TransactionExecutor.java:70)
        at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1800)
        at android.os.Handler.dispatchMessage(Handler.java:106)
        at android.os.Looper.loop(Looper.java:164)
        at android.app.ActivityThread.main(ActivityThread.java:6649)
        at java.lang.reflect.Method.invoke(Native Method)
        at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:493)
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:826)
     Caused by: java.lang.RuntimeException: java.lang.ClassNotFoundException: io.kayvan.io18spike.Fragment2
2018-05-16 13:39:54.439 29258-29258/? E/AndroidRuntime:     at androidx.navigation.fragment.a$a.a(Unknown Source:58)
        at androidx.navigation.fragment.a$a.a(Unknown Source:19)
        at androidx.navigation.i.a(Unknown Source:16)
        at androidx.navigation.i.a(Unknown Source:133)
        at androidx.navigation.i.a(Unknown Source:31)
                ... 36 more
     Caused by: java.lang.ClassNotFoundException: io.kayvan.io18spike.Fragment2
        at java.lang.Class.classForName(Native Method)
        at java.lang.Class.forName(Class.java:453)
        at androidx.navigation.fragment.a$a.a(Unknown Source:45)
                ... 40 more
     Caused by: java.lang.ClassNotFoundException: Didn't find class "io.kayvan.io18spike.Fragment2" on path: DexPathList[[zip file "/system/framework/org.apache.http.legacy.boot.jar", zip file "/data/app/io.kayvan.io18spike-qwaeSphnoJz10eFFCCH9Fw==/base.apk"],nativeLibraryDirectories=[/data/app/io.kayvan.io18spike-qwaeSphnoJz10eFFCCH9Fw==/lib/x86, /system/lib]]
        at dalvik.system.BaseDexClassLoader.findClass(BaseDexClassLoader.java:125)
        at java.lang.ClassLoader.loadClass(ClassLoader.java:379)
        at java.lang.ClassLoader.loadClass(ClassLoader.java:312)
                ... 43 more```

Thanks, this is definitely something we need to fix. As a workaround, you can manually keep each of the Fragments in your navigation graph if you don't reference them elsewhere.