Flutter: Cannot build android apk - flutter

Question

I have been getting errors building apk for flutter. But the app works well while I run it.
I have tried so many fixes like migrating to androidX and upgrading my dependencies but none worked. I recently started getting this error after upgrading flutter. What could be the solution to this?
Error
FAILURE: Build completed with 2 failures.
1: Task failed with an exception.
-----------
* What went wrong:
Execution failed for task ':shared_preferences:verifyReleaseResources'.
> A failure occurred while executing com.android.build.gradle.internal.tasks.Workers$ActionFacade
> Android resource linking failed
/Users/apple/.gradle/caches/transforms-2/files-2.1/d45c258d5b0086b06365ac1a25df0442/core-1.0.0/res/values/values.xml:57:5-88:25: AAPT: error: resource android:attr/fontVariationSettings not found.
/Users/apple/.gradle/caches/transforms-2/files-2.1/d45c258d5b0086b06365ac1a25df0442/core-1.0.0/res/values/values.xml:57:5-88:25: AAPT: error: resource android:attr/ttcIndex not found.
* Try:
Run with --stacktrace option to get the stack trace. Run with --info or --debug option to get more log output. Run with --scan to get full insights.
==============================================================================
2: Task failed with an exception.
-----------
* What went wrong:
Execution failed for task ':path_provider:verifyReleaseResources'.
> A failure occurred while executing com.android.build.gradle.internal.tasks.Workers$ActionFacade
> Android resource linking failed
/Users/apple/.gradle/caches/transforms-2/files-2.1/d45c258d5b0086b06365ac1a25df0442/core-1.0.0/res/values/values.xml:57:5-88:25: AAPT: error: resource android:attr/fontVariationSettings not found.
/Users/apple/.gradle/caches/transforms-2/files-2.1/d45c258d5b0086b06365ac1a25df0442/core-1.0.0/res/values/values.xml:57:5-88:25: AAPT: error: resource android:attr/ttcIndex not found.
* Try:
Run with --stacktrace option to get the stack trace. Run with --info or --debug option to get more log output. Run with --scan to get full insights.
build.gradle
def localProperties = new Properties()
def localPropertiesFile = rootProject.file('local.properties')
if (localPropertiesFile.exists()) {
localPropertiesFile.withReader('UTF-8') { reader ->
localProperties.load(reader)
}
}
def flutterRoot = localProperties.getProperty('flutter.sdk')
if (flutterRoot == null) {
throw new GradleException("Flutter SDK not found. Define location with flutter.sdk in the local.properties file.")
}
def flutterVersionCode = localProperties.getProperty('flutter.versionCode')
if (flutterVersionCode == null) {
flutterVersionCode = '1'
}
def flutterVersionName = localProperties.getProperty('flutter.versionName')
if (flutterVersionName == null) {
flutterVersionName = '1.0'
}
apply plugin: 'com.android.application'
apply plugin: 'kotlin-android'
apply from: "$flutterRoot/packages/flutter_tools/gradle/flutter.gradle"
android {
compileSdkVersion 29
sourceSets {
main.java.srcDirs += 'src/main/kotlin'
}
lintOptions {
disable 'InvalidPackage'
}
defaultConfig {
// TODO: Specify your own unique Application ID (https://developer.android.com/studio/build/application-id.html).
applicationId "com.miraclecentre.bnotion.ben.maf_mentor"
minSdkVersion 16
targetSdkVersion 29
multiDexEnabled true
versionCode flutterVersionCode.toInteger()
versionName flutterVersionName
testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
}
buildTypes {
release {
// TODO: Add your own signing config for the release build.
// Signing with the debug keys for now, so `flutter run --release` works.
signingConfig signingConfigs.debug
}
}
}
flutter {
source '../..'
}
dependencies {
implementation "org.jetbrains.kotlin:kotlin-stdlib-jdk7:$kotlin_version"
implementation 'com.android.support:multidex:1.0.3'
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'
}

Answer 1

Try changing your targetSdkVersion to 28.
That's the only fix I've run across. But when I figure out why that is, I'll come back and update.
EDIT:
update your shared_pref version reference to the most recent one.
After that's done run
flutter pub cache repair

Answer 2

try :
flutter clean
Wait for it to delete older iOS and Android build files.
Then run again:
flutter build apk

Answer 3

Solved this by changing build.gradle file,
Go to,
[project_folder]/external_package/flutter_plugin/[problem_causing_plugin_name]/android/build.gradle/
Change compileSdkVersion 27 to compileSdkVersion 28
then, run Flutter clean and Flutter pub get, and try to create release Apk.