cannot build app due to compile sdk version

[sync-by-unito]

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!

┆Issue is synchronized with this Asana task by Unito

[sync-by-unito]

➤ nationdata-it commented:

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

[sync-by-unito]

➤ Luan Menezes commented:

i have the same problem, with android API 29