While updating compileSdkVersion & targetSdkVersion to 26 - duplicate value for resource 'attr/fontFamily' with config

Issue

I'm updating my apps compile & target SDK version from 23 to 26 (Android 8.0). But after update, getting following error:

error: duplicate value for resource 'attr/fontFamily' with config '.

Having following support libraries now in gradle:

implementation 'com.android.support:support-v4:26.1.0'
implementation 'com.android.support:cardview-v7:26.1.0'
implementation 'com.android.support:appcompat-v7:26.1.0'
implementation 'com.android.support:design:26.1.0'

Please don't suggest to downgrade targetSdkVersion to 25. Don't suggest this question as well: Duplicate value for resource 'attr/font' with config "

Solution

Basically the issue was of an older dependency used in app to use RobotoTextView. I've been able to resolve this issue by updating this library.

from:

implementation 'com.github.johnkil.android-robototextview:robototextview:2.5.0'

to:

implementation 'com.github.johnkil.android-robototextview:robototextview:4.0.0'

Answered By - Akhtar Khan