Tested across 6 machines running OS X versions from 10.8.5 - 10.9.3 using the latest JUCE demo plugin from today (commit: 0147476), and loaded using the introducer built from the same commit, I am seeing crashes happen with a very simple recipe in both WaveLab and Cubase.
The ability to make it crash seems largely dependant on the version of WaveLab or Cubase you are running (I haven't yet tested Nuendo, but I wouldn’t be surprised if this was happening there also).
WaveLab versions tested:
Cubase versions tested:
The recipe is the same in both applications; open the DAW, load the demo, click just once in the body of the plugin (not the title bar), and quit using the WaveLab/Cubase menu.
Some of the crash logs do differ and occasionally the application will hang for a while before finally crashing. I have found crashing the plugin to be most reproducible in WaveLab 7.2.1 and 8.0.0, on one machine loading the 32bit variant of WaveLab made it more likely to crash, on other machines I found particular versions show this bug 100% or 0% of the time, others show the bug intermittently, it's not yet clear why this is.
The bug was first reported to me by a developer at Steinberg, and further testing shows this to occur in the JUCE demo. I will of course be contacting them with these findings but I thought you would like to know.
I also have a whole load of crash logs if you would like me to send them your way? although the crash looks like it might be caused from a dangling pointer, it has a tendency to change, however we normally arrive at 'objc_msgSend' or '_class_initialize' from the 'libobjc.A.dylib' library, I saw no more clues from debugging unfortunately.
If you would like any more information then let me know, I am happy to help in whatever way I can, I could for example put you in contact with the developer I spoke with at Steinberg.