Android build error when using Cordova platform android@9.0.0 or newer

[nationdata-it]

Description:

OneSignalPlugin: WARNING: OneSignalPlugin: Downgraded 'com.android.support:28.+' -> 28 to prevent compile errors! Recommend updating your project's compileSdkVersion!

Environment

Ionic:

Ionic CLI : 6.1.0 (/Users/.nvm/versions/node/v10.16.3/lib/node_modules/@ionic/cli)
Ionic Framework : @ionic/angular 4.6.0
@angular-devkit/build-angular : 0.13.9
@angular-devkit/schematics : 7.2.4
@angular/cli : 7.2.4
@ionic/angular-toolkit : 1.3.0

Cordova:

Cordova CLI : 10.0.0
Cordova Platforms : android 9.0.0
Cordova Plugins : cordova-plugin-ionic-keyboard 2.1.3, cordova-plugin-ionic-webview 4.1.1, (and 25 other plugins)

Steps to Reproduce Issue:

1. ionic cordova build android

Anything else:

(crash stacktraces, as well as any other information here)

Task :app:mergeDebugAssets
OneSignalPlugin: WARNING: OneSignalPlugin: Downgraded 'com.android.support:28.+' -> 28 to prevent compile errors! Recommend updating your project's compileSdkVersion!

[nationdata-it]

after removing plugin
ionic cordova plugin rm onesignal-cordova-plugin
build is fine

[luanmnz]

i have the same problem, with android API 29

[rgomezp]

Also reported with other android API versions:
#658

[TraceDeTrail]

Hello,
Is a patch planned soon? The use of Api 29 is now required on Android...
Thank you !

[jpturski]

Any workaround available?

[FbPalmabit]

My temporary solution:

• downgrade Cordova Platforms at ^8
• remove/add platform and plugins
• in config.xml:

<platform name="android">
       <preference name="android-targetSdkVersion" value="29" />
       ...
</platform>

Now APK has target 29

[jkasten2]

This is now fixed part of the OneSignal-Gradle-Plugin 0.12.9 update used by this plugin. You may have to do a clean build for this new version to be pulled in.