How to fix "Execution failed for task ':app:processDebugResources'. > Android resource linking failed"[Android/Flutter]

Question

It happened out of nowhere. One day I was running my code which was working just fine, and the next day, without touching my build.gradle files or any other build files this error popped up.

I have tried a lot of different solutions like changing my buildToolsVersion or setting a specific flag of AAPT(can't remember which) to false. Nothing works. My app\build.gradle file:

 android {
 compileSdkVersion 27
 buildToolsVersion '27.0.3'

 sourceSets {
     main.java.srcDirs += 'src/main/kotlin'
 } 

 lintOptions {
     disable 'InvalidPackage'
 }

 defaultConfig {
     // TODO: Specify your own unique Application ID 
     (https://developer.android.com/studio/build/application-id.html).
     applicationId "com.skydevs.bookx"
     minSdkVersion 16
     targetSdkVersion 27
     versionCode flutterVersionCode.toInteger()
     versionName flutterVersionName
     testInstrumentationRunner 
     "android.support.test.runner.AndroidJUnitRunner"
 }

 buildTypes {
     release {
         // TODO: Add your own signing config for the release build.
         // Signing with the debug keys for now, so `flutter run --release` 
         works.
         signingConfig signingConfigs.debug
     }
 }
 }

 flutter {
     source '../..'
 }

 dependencies {
   implementation "org.jetbrains.kotlin:kotlin-stdlib-jdk7:$kotlin_version"
   testImplementation 'junit:junit:4.12'
   androidTestImplementation 'com.android.support.test:runner:1.0.2'
   androidTestImplementation 'com.android.support.test.espresso:espresso- 
   core:3.0.2'
   implementation 'com.google.firebase:firebase-core:16.0.1'
 }

 apply plugin: 'com.google.gms.google-services'

The error I'm getting is:

Execution failed for task ':app:processDebugResources'.
> Android resource linking failed
  Output:  C:\Users\baada\AndroidStudioProjects\bookx\build\app\intermediates\incremental\mergeDebugResources\merged.dir\values-v28\values-v28.xml:7: error: resource android:attr/dialogCornerRadius not found.
  C:\Users\baada\AndroidStudioProjects\bookx\build\app\intermediates\incremental\mergeDebugResources\merged.dir\values-v28\values-v28.xml:11: error: resource android:attr/dialogCornerRadius not found.
  C:\Users\baada\AndroidStudioProjects\bookx\build\app\intermediates\incremental\mergeDebugResources\merged.dir\values\values.xml:905: error: resource android:attr/fontVariationSettings not found.
  C:\Users\baada\AndroidStudioProjects\bookx\build\app\intermediates\incremental\mergeDebugResources\merged.dir\values\values.xml:905: error: resource android:attr/ttcIndex not found.
  error: failed linking references.

  Command: C:\Users\baada\.gradle\caches\transforms-1\files-1.1\aapt2-3.2.1-4818971-windows.jar\a5cc63922d025d4315a498efa486650c\aapt2-3.2.1-4818971-windows\aapt2.exe link -I\
          C:\Users\baada\AppData\Local\Android\sdk\platforms\android-27\android.jar\
          --manifest\
          C:\Users\baada\AndroidStudioProjects\bookx\build\app\intermediates\merged_manifests\debug\processDebugManifest\merged\AndroidManifest.xml\
          -o\
          C:\Users\baada\AndroidStudioProjects\bookx\build\app\intermediates\processed_res\debug\processDebugResources\out\resources-debug.ap_\
          -R\
          @C:\Users\baada\AndroidStudioProjects\bookx\build\app\intermediates\incremental\processDebugResources\resources-list-for-resources-debug.ap_.txt\
          --auto-add-overlay\
          --java\
          C:\Users\baada\AndroidStudioProjects\bookx\build\app\generated\not_namespaced_r_class_sources\debug\processDebugResources\r\
          --custom-package\
          com.example.bookx\
          -0\
          apk\
          --output-text-symbols\
          C:\Users\baada\AndroidStudioProjects\bookx\build\app\intermediates\symbols\debug\R.txt\
          --no-version-vectors
  Daemon:  AAPT2 aapt2-3.2.1-4818971-windows Daemon #0
  Output:  C:\Users\baada\.gradle\caches\transforms-1\files-1.1\appcompat-1.0.2.aar\aa44270b14856bd5a0b17a3c0a45cb34\res\values-v28\values-v28.xml:9:5-12:13: AAPT: error: resource android:attr/dialogCornerRadius not found.

  C:\Users\baada\AndroidStudioProjects\bookx\build\app\intermediates\incremental\mergeDebugResources\merged.dir\values-v28\values-v28.xml:11: AAPT: error: resource android:attr/dialogCornerRadius not found.

  C:\Users\baada\.gradle\caches\transforms-1\files-1.1\core-1.0.1.aar\bc8b94f938baa5558925fd51b49cb6bf\res\values\values.xml:89:5-125:25: AAPT: error: resource android:attr/fontVariationSettings not found.

  C:\Users\baada\.gradle\caches\transforms-1\files-1.1\core-1.0.1.aar\bc8b94f938baa5558925fd51b49cb6bf\res\values\values.xml:89:5-125:25: AAPT: error: resource android:attr/ttcIndex not found.

  error: failed linking references.
  Command: C:\Users\baada\.gradle\caches\transforms-1\files-1.1\aapt2-3.2.1-4818971-windows.jar\a5cc63922d025d4315a498efa486650c\aapt2-3.2.1-4818971-windows\aapt2.exe link -I\
          C:\Users\baada\AppData\Local\Android\sdk\platforms\android-27\android.jar\
          --manifest\
          C:\Users\baada\AndroidStudioProjects\bookx\build\app\intermediates\merged_manifests\debug\processDebugManifest\merged\AndroidManifest.xml\
          -o\
          C:\Users\baada\AndroidStudioProjects\bookx\build\app\intermediates\processed_res\debug\processDebugResources\out\resources-debug.ap_\
          -R\
          @C:\Users\baada\AndroidStudioProjects\bookx\build\app\intermediates\incremental\processDebugResources\resources-list-for-resources-debug.ap_.txt\
          --auto-add-overlay\
          --java\
          C:\Users\baada\AndroidStudioProjects\bookx\build\app\generated\not_namespaced_r_class_sources\debug\processDebugResources\r\
          --custom-package\
          com.example.bookx\
          -0\
          apk\
          --output-text-symbols\
          C:\Users\baada\AndroidStudioProjects\bookx\build\app\intermediates\symbols\debug\R.txt\
          --no-version-vectors
  Daemon:  AAPT2 aapt2-3.2.1-4818971-windows Daemon #0

Answer 1

Today, I got the same error at my project which I was working on yesterday without any problem.

Some upgrade causes this error IMO, my solution is:

• Open the project via Android Studio

• Open android/build.gradle and android/app/build.gradle

• Just correct things what IDE warns about, it usually warns your SDK, Kotlin and Gradle versions etc.

It's not mandatory but you can check your .bashrc exports or environment variables, sometimes it can fix some problems.

Edit: When you are updating your SDK versions, don't forget to upgrade also your project dependencies.