On Mar 19, 2018, at 12:10 AM, Tim Johnson wrote:
> Updates being applied at time of crash:
>
> update-mt.421.mcm
> System-mt.963
>
> (I was also unable to update a 5.1 image via trunk past some point  
> on OS X without a crash.  It might have been this update there too,  
> but I don't have the details to confirm for now.)
>

Yes.  Crash duplicated in the following configuration:

* OS X 10.12.6
* fresh 5.1 64-bit image
* Cog Spur VM 64-bit 2018-03-08-0952

Again, while trying to apply update #421 after applying all updates  
up to and including #420.

THanks,
TIm