Testing for macOS 10.12 Sierra
Sierra will ship on September 20, so I’ve been testing my apps with the Golden Master (GM). Unfortunately, GM doesn’t mean what it used to. Not only is the macOS 10.12 GM different bits than customers will install (same with the Xcode GM) but there are actually multiple GMs.
The first GM that I downloaded was build 16A319. Then I heard about 16A320 and 16A322. There was probably one in between those, too.
When a new GM is released, it does not appear in the Mac App Store as an update. You have to delete the Install macOS Sierra.app, redownload the installer, and install the whole thing again.
I have been using VMware for testing. Despite the update to VMware 8.5, VMware will not automatically install Sierra for me. If I create a new VM and tell it to use the installer app, VMware reports an error: “Unable to create the installation medium.”. [Update: See below.]
There are two methods that have worked for me:
Copy and open a Mac OS X 10.11 VM, drag the installer app to its Finder, then run installer. (Then, optionally, delete the installer, empty the trash, and compact.)
Create a blank disk image called Sierra, then make an installer disk:
sudo /Applications/Install\ macOS\ Sierra.app/Contents/Resources/createinstallmedia --volume /Volumes/Sierra --applicationpath /Applications/Install\ macOS\ Sierra.app
And tell VMware to create the VM based on the disk image.
Unfortunately, the Sierra GM is still rather buggy.
Update (2016-09-15): Another GM build, 16A323, has been released, and I’m told that the “official” release next week will be different still.
Emma Rios reports that the second GM still has an issue with slow Wi-Fi.
Update (2016-09-20): The final build from the Mac App Store is 16A323.
