I wonder... Are the keychain passwords on all those other Macs the same as their login passwords, or do they differ as mine does?
They are all the same.
Well, that called for an experiment, so I
- made my keychain password the same as my login password in my Sierra boot account,
- booted into High Sierra,
- used migration assistant to import the changed Sierra boot account,
- logged in to the newly imported account,
- and VOILA! There, just like magic, was my complete keychain.
Bug identified and reported...ball's in Apple's court..
More: Oops! Although I logged out and back in with no issues, I forgot to restart to see if things remained copacetic, and I also forgot to make my keychain and login passwords different and see if things remained copacetic after a restart...and I've erased the volume.
Oh, well, another project.
Sidenote: The first time I logged in to the newly imported account, all my login items launched as expected, but when I logged out and back in they didn't launch and were gone from System Prefs > Users & Groups > Login Items.
Bug reported to Apple
