Widget handle size not updated in captured test images from systems with HiDPI displays
Widget tests failing on big Mac differ in how large the widget handles are. See, e.g., https://open.cdash.org/testDetails.php?test=573864647&build=5015238.
The problem is the widget handle sizes are computed with respect to the HiDPI render window size in physical pixels, but the handle sizes are not updated when the test image is captured.
Likely solution: update the widget handles when the render window modification time is changed.