Styjun

I migrated my app to androidx, and now in the released version, I'm getting that error. It works fine in all my tests, even the test lab doesn't find that error.

I've checked through every reference for it and they're all fine.

The line with the error:

 private MaterialButton mShiftStartDate;

private void getVars() 
.
 mShiftStartDate = v.findViewById(R.id.shift_start_date_tv);
.

and the xml:

 <com.google.android.material.button.MaterialButton
 style="@style/Widget.MaterialComponents.Button.OutlinedButton"
 android:id="@id/shift_start_date_tv"
 android:layout_width="wrap_content"
 android:layout_height="wrap_content"
 android:layout_marginTop="8dp"
 android:textSize="18sp"
 android:visibility="visible"
 app:layout_constraintEnd_toEndOf="@id/shift_start_date_label"
 app:layout_constraintHorizontal_chainStyle="spread_inside"
 app:layout_constraintStart_toStartOf="@id/shift_start_date_label"
 app:layout_constraintTop_toBottomOf="@id/shift_start_date_label"
 tools:text="10/10/18" />

and parts of build.gradle

 defaultConfig 
 applicationId appId
 targetSdkVersion 28
 minSdkVersion 19
 versionCode buildCode
 versionName versionMajor+"."+versionMinor+"."+versionRevision+"."+versionBuild
 resValue "string", "CURRENT_VERSION", versionName
 
 compileOptions 
 sourceCompatibility 1.8
 targetCompatibility 1.8
 
dependencies 
 implementation fileTree(include: ['*.jar'], dir: 'libs')
 implementation 'androidx.legacy:legacy-support-v4:1.0.0'
 implementation 'androidx.appcompat:appcompat:1.1.0-alpha03'
 implementation 'com.google.android.material:material:1.1.0-alpha04'
 implementation 'androidx.recyclerview:recyclerview:1.1.0-alpha03'
 implementation 'androidx.browser:browser:1.0.0'
 implementation 'androidx.constraintlayout:constraintlayout:2.0.0-alpha3'
 implementation 'androidx.preference:preference:1.1.0-alpha04'
 implementation 'androidx.annotation:annotation:1.1.0-alpha02'
 implementation 'com.android.support:appcompat-v7:28.0.0'
 implementation 'android.arch.navigation:navigation-fragment:1.0.0'
 implementation 'android.arch.navigation:navigation-ui:1.0.0'
 implementation 'com.google.android.gms:play-services-ads-lite:17.2.0'
 implementation 'com.google.android.gms:play-services-oss-licenses:16.0.2'
 implementation 'org.jetbrains:annotations:17.0.0'

Searching for it doesn't turn up any other examples of the problem. The only thing I can think of is proguard is renaming something it shouldn't. Since I can't manage to reproduce it (It's only happened to 5 users, but 26 times for them in all) in any emulator or using test devices, I can't test something like

-keep class androidx.appcompat.widget.** *;

which is all I can think to do.

you have a duplicate dependency there:

implementation 'androidx.appcompat:appcompat:1.1.0-alpha03'
// implementation 'com.android.support:appcompat-v7:28.0.0'

and there is no widget N. the ProGuard mapping might tell what it actually is.

-keep,includedescriptorclass class androidx.appcompat.widget.** *; 

using stable versions might also help to sort out unexpected results.