This happened to our Waveform app and plugins in Release builds (not debug though).
I tired building the JUCE demo but that seemed to be ok though so still digging for a proper report.
This happened with both the 11.1 & 10.13 SDKs targeting 10.9.
Thanks for reporting, there was indeed a bug in that commit with JUCE_COREGRAPHICS_RENDER_WITH_MULTIPLE_PAINT_CALLS enabled. We’ll be doing a bugfix release very shortly with this fix in: