👉 LeakCanary 
アプリが起動できずにこんなの出ましたけど。
2022-02-28 21:18:29.578 16816-16816/com.benigumo.apn D/AndroidRuntime: Shutting down VM
2022-02-28 21:18:29.589 16816-16816/com.benigumo.apn E/AndroidRuntime: FATAL EXCEPTION: main
Process: com.example.app, PID: 16816
java.lang.NullPointerException
at q5.c$c.b(:112)
at q5.c$c.f(:154)
at p5.f.d(:233)
at c7.x$a.c(:46)
at p5.b$a.a(:38)
at c7.x$a.b(:43)
at q5.b$b.a(:25)
at q5.b$b.add(:23)
at android.view.WindowManagerGlobal.addView(WindowManagerGlobal.java:393)
at android.view.WindowManagerImpl.addView(WindowManagerImpl.java:133)
at android.app.ActivityThread.handleResumeActivity(ActivityThread.java:4847)
at android.app.servertransaction.ResumeActivityItem.execute(ResumeActivityItem.java:54)
at android.app.servertransaction.ActivityTransactionItem.execute(ActivityTransactionItem.java:45)
at android.app.servertransaction.TransactionExecutor.executeLifecycleState(TransactionExecutor.java:176)
at android.app.servertransaction.TransactionExecutor.execute(TransactionExecutor.java:97)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:2214)
at android.os.Handler.dispatchMessage(Handler.java:106)
at android.os.Looper.loopOnce(Looper.java:201)
at android.os.Looper.loop(Looper.java:288)
at android.app.ActivityThread.main(ActivityThread.java:7842)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:548)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1003)
minifyEnabled false ではクラッシュしない。
回避方法
難読化されている部分は以下の模様。
Fatal Exception: java.lang.NullPointerException
curtains.internal.WindowCallbackWrapper$Companion.getJetpackWrapped (WindowCallbackWrapper.kt:112)
curtains.internal.WindowCallbackWrapper$Companion.unwrap (WindowCallbackWrapper.kt:154)
curtains.WindowsKt.getWrappedCallback (Windows.kt:233)
leakcanary.RootViewWatcher$listener$1.onRootViewAdded (RootViewWatcher.kt:46)
curtains.OnRootViewAddedListener$DefaultImpls.onRootViewsChanged (Listeners.kt:38)
leakcanary.RootViewWatcher$listener$1.onRootViewsChanged (RootViewWatcher.kt:43)
curtains.internal.RootViewsSpy$delegatingViewList$1.add (RootViewsSpy.kt:25)
curtains.internal.RootViewsSpy$delegatingViewList$1.add (RootViewsSpy.kt:23)
android.view.WindowManagerGlobal.addView (WindowManagerGlobal.java:454)
android.view.WindowManagerImpl.addView (WindowManagerImpl.java:121)
...
👉 Obfucation and 2.8.1 version cause an app launch crash · Issue #2286 · square/leakcanary 
書いてあるように、proguard rule に以下を追加で暫定回避できました。
-keep class androidx.appcompat.view.WindowCallbackWrapper { *; }
-keep class android.support.v7.view.WindowCallbackWrapper { *; }
次期バージョンで修正され、不要になるのでしょうが。
👉 Add Proguard rules for WindowCallbackWrapper by carlonzo · Pull Request #33 · square/curtains 
2022-04-08 追記
さらに更新されてる。
-keep class androidx.appcompat.view.WindowCallbackWrapper {
android.view.Window$Callback mWrapped;
}
-keep class android.support.v7.view.WindowCallbackWrapper {
android.view.Window$Callback mWrapped;
}
👉 just keep it · carlonzo/curtains@686b12c 
