If you’re trying to debug compositor layers, for example
to determine whether and where to add RepaintBoundary
widgets, you can use the debugPaintLayerBordersEnabled
flag, which outlines each layer’s bounds in orange,
or the debugRepaintRainbowEnabled flag,
which causes layers to be overlayed with a rotating set of
colors whenever they are repainted.

All of these flags only work in debug mode.
In general, anything in the Flutter framework that starts with
“debug...” only works in debug mode.

Debugging animations

Note:
  The easiest way to debug animations is to slow them down.
  You can do this using the Slow Animations button in
  DevTools’ Inspector view, which slows down the
  animation by 5x. If you want more control over the
  amount of slowness, use the following instructions.