title: SwiftUI: Crash when calling scrollTo method with anchor: .center
body: <p>Not 100% sure if it's caused by the <code>anchor</code> as I just removed it and haven't experienced crash so far (will report back if more crashes happens) - could someone check and help see if that could actually be where the bug is? Going to file an Apple bug as well.</p>
  <p>My view looks like this:</p>
  <pre><code>var body: some View {
      ScrollViewReader { scrollProxy in
          ScrollView {
              if isShowingContent {
                  LazyVStack {
                      ForEach(mo.msgMos.indices, id: \.self) { i in
                          ...
                      }
                  }
              }
          }
          .onChange(of: mo.scrollToIdx) { idx in
              withAnimation {
                  scrollProxy.scrollTo(targetIdx, anchor: .center)
              }
          }
      }
  }
  
  </code></pre>
  <p>And the crash stack looks like this:</p>
  <pre><code>Crashed: com.apple.main-thread
  0  AttributeGraph                 0x1cedce974 AGGraphGetValue + 284
  1  SwiftUI                        0x1addcbe5c _ViewCache.layout.getter + 52
  2  SwiftUI                        0x1addcc2f4 _ViewCache.withPlacementData&lt;A&gt;(_:) + 160
  3  SwiftUI                        0x1addd02d0 closure #1 in IncrementalScrollable.makeTarget(at:anchor:) + 336
  4  SwiftUI                        0x1addd6a9c partial apply for closure #1 in IncrementalScrollable.makeTarget(at:anchor:) + 56
  5  SwiftUI                        0x1ae2241fc HostingScrollView.updateAnimationTarget(_:) + 216
  6  SwiftUI                        0x1ae2245c4 HostingScrollView.bounds.didset + 188
  7  SwiftUI                        0x1ae2244e8 HostingScrollView.bounds.setter + 128
  8  SwiftUI                        0x1ae22444c @objc HostingScrollView.bounds.setter + 44
  9  UIKitCore                      0x1aa494e4c -[UIScrollView setContentOffset:] + 804
  10 UIKitCore                      0x1aa48f1e0 -[UIScrollViewScrollAnimation setProgress:] + 320
  11 UIKitCore                      0x1a95094b8 -[UIAnimator _advanceAnimationsOfType:withTimestamp:] + 276
  12 QuartzCore                     0x1aa8e46a4 CA::Display::DisplayLink::dispatch_items(unsigned long long, unsigned long long, unsigned long long) + 664
  13 QuartzCore                     0x1aa9bb1a0 display_timer_callback(__CFMachPort*, void*, long, void*) + 280
  14 CoreFoundation                 0x1a7633ce4 __CFMachPortPerform + 176
  15 CoreFoundation                 0x1a7658098 __CFRUNLOOP_IS_CALLING_OUT_TO_A_SOURCE1_PERFORM_FUNCTION__ + 60
  16 CoreFoundation                 0x1a7657440 __CFRunLoopDoSource1 + 596
  17 CoreFoundation                 0x1a7651320 __CFRunLoopRun + 2360
  18 CoreFoundation                 0x1a76504bc CFRunLoopRunSpecific + 600
  19 GraphicsServices               0x1be0d5820 GSEventRunModal + 164
  20 UIKitCore                      0x1a9ff4734 -[UIApplication _run] + 1072
  21 UIKitCore                      0x1a9ff9e10 UIApplicationMain + 168
  22 Fablur                         0x102453f8c main + 12 (AppDelegate.swift:12)
  23 libdyld.dylib                  0x1a7317e60 start + 4
  </code></pre>