Flutter-geolocator: java.lang.NullPointerException when getting location in a separate isolate

🐛 Bug Report

I'm getting the error when trying to get location in background process so the plugin runs in a separate isolate using workmanager:

Failed to handle method call
java.lang.NullPointerException: Attempt to invoke virtual method 'java.lang.String android.content.Context.getPackageName()' on a null object reference

Here is some stack trace:

E/MethodChannel#flutter.baseflow.com/google_api_availability/methods( 5234): Failed to handle method call
E/MethodChannel#flutter.baseflow.com/google_api_availability/methods( 5234): java.lang.NullPointerException: Attempt to invoke virtual method 'java.lang.String android.content.Context.getPackageName()' on a null object reference
E/MethodChannel#flutter.baseflow.com/google_api_availability/methods( 5234):    at com.google.android.gms.common.GooglePlayServicesUtilLight.isGooglePlayServicesAvailable(Unknown Source:12)
E/MethodChannel#flutter.baseflow.com/google_api_availability/methods( 5234):    at com.google.android.gms.common.GoogleApiAvailabilityLight.isGooglePlayServicesAvailable(Unknown Source:5)
E/MethodChannel#flutter.baseflow.com/google_api_availability/methods( 5234):    at com.google.android.gms.common.GoogleApiAvailability.isGooglePlayServicesAvailable(Unknown Source:94)
E/MethodChannel#flutter.baseflow.com/google_api_availability/methods( 5234):    at com.google.android.gms.common.GoogleApiAvailabilityLight.isGooglePlayServicesAvailable(Unknown Source:3)
E/MethodChannel#flutter.baseflow.com/google_api_availability/methods( 5234):    at com.google.android.gms.common.GoogleApiAvailability.isGooglePlayServicesAvailable(Unknown Source:93)
E/MethodChannel#flutter.baseflow.com/google_api_availability/methods( 5234):    at com.baseflow.googleapiavailability.GoogleApiAvailabilityPlugin.onMethodCall(GoogleApiAvailabilityPlugin.java:105)
E/MethodChannel#flutter.baseflow.com/google_api_availability/methods( 5234):    at io.flutter.plugin.common.MethodChannel$IncomingMethodCallHandler.onMessage(MethodChannel.java:231)
E/MethodChannel#flutter.baseflow.com/google_api_availability/methods( 5234):    at io.flutter.embedding.engine.dart.DartMessenger.handleMessageFromDart(DartMessenger.java:93)
E/MethodChannel#flutter.baseflow.com/google_api_availability/methods( 5234):    at io.flutter.embedding.engine.FlutterJNI.handlePlatformMessage(FlutterJNI.java:642)
E/MethodChannel#flutter.baseflow.com/google_api_availability/methods( 5234):    at android.os.MessageQueue.nativePollOnce(Native Method)
E/MethodChannel#flutter.baseflow.com/google_api_availability/methods( 5234):    at android.os.MessageQueue.next(MessageQueue.java:336)
E/MethodChannel#flutter.baseflow.com/google_api_availability/methods( 5234):    at android.os.Looper.loop(Looper.java:174)
E/MethodChannel#flutter.baseflow.com/google_api_availability/methods( 5234):    at android.app.ActivityThread.main(ActivityThread.java:7356)
E/MethodChannel#flutter.baseflow.com/google_api_availability/methods( 5234):    at java.lang.reflect.Method.invoke(Native Method)
E/MethodChannel#flutter.baseflow.com/google_api_availability/methods( 5234):    at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:492)
E/MethodChannel#flutter.baseflow.com/google_api_availability/methods( 5234):    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:930)

Reproduction steps

I've created a sample app to reproduce the issue: https://github.com/estevez-dev/sample_flutter_app
It is preconfigured to run in Gitpod. Just tap floating button to start background task and you will get an exception on getCurrentPosition.
Please note that app will not request location permission, you need to allow it manually from Android settings.

Configuration

Plugin version: 5.3.0

Platform:

• [ ] :iphone: iOS
• [x] :robot: Android