VirtualBox 6.0.2 assertion failed while starting a macOS VM

[ilg]

My physical computer is a Mac Mini running macOS 10.13.6 and VirtualBox 5.2.2. Among several VMs I have, one is a macOS 10.10.

Today I tried to upgrade VirtualBox to 6.0.2, including the extpack, but when I tried to start the macOS VM, I got a meesage box with an error and the session did not start.

Checking the log, the only lines that seem to be related to VirtualBox are:

ilg-mini-harlescu:tmp ilg$ grep Virtual ~/Desktop/system.log
Jan 20 18:10:48 ilg-mini-harlescu VirtualBox[92143]: assertion failed: 17G4015: libxpc.dylib + 75013 [0BC7AD67-671D-31D4-8B88-C317B8379598]: 0x89
Jan 20 18:10:48 ilg-mini-harlescu VirtualBox[92143]: objc[92143]: Class FIFinderSyncExtensionHost is implemented in both /System/Library/PrivateFrameworks/FinderKit.framework/Versions/A/FinderKit (0x7fffa2078cd0) and /System/Library/PrivateFrameworks/FileProvider.framework/OverrideBundles/FinderSyncCollaborationFileProviderOverride.bundle/Contents/MacOS/FinderSyncCollaborationFileProviderOverride (0x11caa6cd8). One of the two will be used. Which one is undefined.
Jan 20 18:11:24 ilg-mini-harlescu VirtualBox[92143]: BUG in libdispatch client: kevent[mach_recv] monitored resource vanished before the source cancel handler was invoked

Jan 20 18:20:52 ilg-mini-harlescu VirtualBox[914]: assertion failed: 17G4015: libxpc.dylib + 75013 [0BC7AD67-671D-31D4-8B88-C317B8379598]: 0x89
Jan 20 18:20:52 ilg-mini-harlescu VirtualBox[914]: objc[914]: Class FIFinderSyncExtensionHost is implemented in both /System/Library/PrivateFrameworks/FinderKit.framework/Versions/A/FinderKit (0x7fff9413fcd0) and /System/Library/PrivateFrameworks/FileProvider.framework/OverrideBundles/FinderSyncCollaborationFileProviderOverride.bundle/Contents/MacOS/FinderSyncCollaborationFileProviderOverride (0x1214becd8). One of the two will be used. Which one is undefined.
Jan 20 18:25:47 ilg-mini-harlescu VirtualBox[914]: BUG in libdispatch client: kevent[mach_recv] monitored resource vanished before the source cancel handler was invoked

I removed 6.0.2, reinstalled 5.2.22 and the same macOS VM started normally, so at least 6.x did not damage it.

My understanding of the log lines is that this new version of VirtualBox running on macOS has a problem and an assert is triggered.

The condition to have the class FIFinderSyncExtensionHost defined in two frameworks seems to be a known problem of macOS (​https://stackoverflow.com/questions/46999695/class-fifindersyncextensionhost-is-implemented-in-both-warning-in-xcode-si), and I think it should not trigger the assert, the program should find a way to cope with this condition, as versions 5.x already did.

[Socratis]

Duplicate of #18361.

[janitor]

#18361