[Bug] Freeze in AudioPluginHost when scanning AU plugins and cancel

JUCE 5.4.7. Mac OS X 10.14.6.

When running the AudioPluginHost, clear the plugin list, and run a new scan on AU plugins. Assuming you have the default available Mac OS AUs, this will start populating the list.

Now, click Cancel in the “Scanning for plugins…” dialog, in the middle of the process. It freezes, with the dialog stuck on top.

In the Xcode debugger, click “pause program executions”. It appears to be stuck in a wait condition inside the message thread (?) - I’m not sure how to read this…