Mojave Hangs

I’ve a MacBookPro9,2 at home. It’s older but I like it. Has sufficient horsepower and the memory, disk, battery are all still maintainable. I attempted the OS X Mojave upgrade and it would complete but hang at the gray Apple logo on the final reboot before kicking off the setup/welcome app.   I tried all the reported fixes without success.

The Fix

Abandoning the reported solutions I dug deeper, and did:

1. Reboot in recovery mode (Command-R power)
2. Open the Terminal
3. Look in the target volume’s /var/log

I found there an install.log and read that.  Near the end there was an attempt to remount the drive with a specific hardware option and it was returning an error 22. This mount option must be new to Mojave since prior upgrades have worked.

So, I bought a new SSD, installed on that, and Viola! Apparently the 750GB HGST drive I had didn’t support the newly incorporated feature.

Would have been nice if the install detected that before it blew hours of transferring data etc.