I have a CoordinatorLayout that I am using as a fragment container, and I started getting leak reports after fragments are getting destroyed, because their View's are referenced by the container's mPreSortedChildren.

Looking at the ViewGroup source, it seems like that gets cleared when buildOrderedChildList is called, but I'm not fully sure what would trigger that (seems like a draw will, but not sure if there are conditions).

Is there something LeakCanary (or plumber) can do about that, or would it have to be a framework fix (I can repro on a Pixel 2 running Android 11)?

Using LeakCanary 2.4

LeakTrace information

┬───
│ GC Root: System class
│
├─ android.view.inputmethod.InputMethodManager class
│    Leaking: NO (InputMethodManager↓ is not leaking and a class is never leaking)
│    ↓ static InputMethodManager.sInstance
├─ android.view.inputmethod.InputMethodManager instance
│    Leaking: NO (ViewRootImpl↓ is not leaking and InputMethodManager is a singleton)
│    ↓ InputMethodManager.mCurRootView
├─ android.view.ViewRootImpl instance
│    Leaking: NO (MyRecyclerView↓ is not leaking and ViewRootImpl#mView is not null)
│    ↓ ViewRootImpl.mAttachInfo
├─ android.view.View$AttachInfo instance
│    Leaking: NO (MyRecyclerView↓ is not leaking)
│    ↓ View$AttachInfo.mScrollContainers
├─ java.util.ArrayList instance
│    Leaking: NO (MyRecyclerView↓ is not leaking)
│    ↓ ArrayList.elementData
├─ java.lang.Object[] array
│    Leaking: NO (MyRecyclerView↓ is not leaking)
│    ↓ Object[].[3]
├─ com.myapp.MyRecyclerView instance
│    Leaking: NO (ConstraintLayout↓ is not leaking and View attached)
│    mContext instance of com.myapp.MainActivity with mDestroyed = false
│    View.parent androidx.constraintlayout.widget.ConstraintLayout attached as well
│    View#mParent is set
│    View#mAttachInfo is not null (view attached)
│    View.mID = R.id.list
│    View.mWindowAttachCount = 1
│    ↓ MyRecyclerView.mParent
├─ androidx.constraintlayout.widget.ConstraintLayout instance
│    Leaking: NO (CoordinatorLayout↓ is not leaking and View attached)
│    mContext instance of com.myapp.MainActivity with mDestroyed = false
│    View.parent androidx.coordinatorlayout.widget.CoordinatorLayout attached as well
│    View#mParent is set
│    View#mAttachInfo is not null (view attached)
│    View.mWindowAttachCount = 1
│    ↓ ConstraintLayout.mParent
├─ androidx.coordinatorlayout.widget.CoordinatorLayout instance
│    Leaking: NO (View attached)
│    mContext instance of com.myapp.MainActivity with mDestroyed = false
│    View.parent androidx.constraintlayout.widget.ConstraintLayout attached as well
│    View#mParent is set
│    View#mAttachInfo is not null (view attached)
│    View.mID = R.id.fragmentContainer
│    View.mWindowAttachCount = 1
│    ↓ CoordinatorLayout.mPreSortedChildren
│                        ~~~~~~~~~~~~~~~~~~
├─ java.util.ArrayList instance
│    Leaking: UNKNOWN
│    ↓ ArrayList.elementData
│                ~~~~~~~~~~~
├─ java.lang.Object[] array
│    Leaking: UNKNOWN
│    ↓ Object[].[2]
│               ~~~
╰→ androidx.constraintlayout.widget.ConstraintLayout instance
​     Leaking: YES (ObjectWatcher was watching this because com.myapp.ToastFragment received Fragment#onDestroyView() callback (references to its views should be cleared to prevent leaks))
​     key = 2b7e412c-ad06-4dd5-a175-2fb836a69564
​     watchDurationMillis = 5988
​     retainedDurationMillis = 959
​     mContext instance of com.myapp.MainActivity with mDestroyed = false
​     View#mParent is null
​     View#mAttachInfo is null (view detached)
​     View.mWindowAttachCount = 1
====================================