Unable to start service rekab.app.background_locator.IsolateHolderService - flutter

Question

I use background_locator to track geo_location when the user activates tracking by clicking a button. The location is then posted to an API, which logs it in a database.
The feature works in debug mode, but crashes with the following exception, in release mode:
E/AndroidRuntime(31736): FATAL EXCEPTION: main
E/AndroidRuntime(31736): Process: za.co.liquidedge.celltrack, PID: 31736
E/AndroidRuntime(31736): java.lang.RuntimeException: Unable to start service rekab.app.background_locator.IsolateHolderServiceolateHolderService (has extras) }: java.lang.RuntimeException: Missing type parameter.
E/AndroidRuntime(31736): at android.app.ActivityThread.handleServiceArgs(ActivityThread.java:4759)
E/AndroidRuntime(31736): at android.app.ActivityThread.access$1900(ActivityThread.java:301)
E/AndroidRuntime(31736): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:2186)
E/AndroidRuntime(31736): at android.os.Handler.dispatchMessage(Handler.java:106)6)
E/AndroidRuntime(31736): at android.os.Looper.loop(Looper.java:246) a:8506)
E/AndroidRuntime(31736): at android.app.ActivityThread.main(ActivityThread.java:8506) aller.run(RuntimeInit.java:602)
E/AndroidRuntime(31736): at com.android.internal.os.RuntimeInit$MethodAndArgsC.java:1130)aller.run(RuntimeInit.java:602) r.
E/AndroidRuntime(31736): at com.android.internal.os.ZygoteInit.main(ZygoteInite:26).java:1130)
E/AndroidRuntime(31736): Caused by: java.lang.RuntimeException: Missing type parametece:0)r. )
E/AndroidRuntime(31736): at d.c.c.O.a.getSuperclassTypeParameter(Unknown Sourc23)e:26) onStartCommand(:11)
E/AndroidRuntime(31736): at d.c.c.O.a.<init>(Unknown Source:7) ityThread.java:4741)
E/AndroidRuntime(31736): at rekab.app.background_locator.e.<init>(Unknown Source:0)
E/AndroidRuntime(31736): at rekab.app.background_locator.f.b(Unknown Source:24)
E/AndroidRuntime(31736): at rekab.app.background_locator.g.d.a(Unknown Source:23)
E/AndroidRuntime(31736): at rekab.app.background_locator.IsolateHolderService.onStartCommand(:11)
E/AndroidRuntime(31736): at android.app.ActivityThread.handleServiceArgs(ActivityThread.java:4741)

Answer 1

I fixed this issue by adding these rules to android/app/proguard-rules.pro
# Gson uses generic type information stored in a class file when working with fields. Proguard
# removes such information by default, so configure it to keep all of it.
-keepattributes Signature
# Gson specific classes
-keep class sun.misc.Unsafe { *; }
#-keep class com.google.gson.stream.** { *; }
# Application classes that will be serialized/deserialized over Gson
-keep class com.google.gson.examples.android.model.** { *; }