macOS Mojave CalendarAgent runaway process I'm using Google Calendars on more than one account.

Everything was fine in macOS High Sierra, but after upgrading to macOS Mojave, the CalendarAgent process sat at about 100% CPU, continuously.

The only way I could hold the fans quiet is by freezing it by running:

killall -STOP CalendarAgent

But that's not really a solution. All it does is prevent the runaway process from executing. Consequently, the Calendar.app client doesn't work anymore.

Anyone encounter the same problem? Any ideas on a proper fix?
Well, it appears that somehow the upgrade must have left the calendar info in a weird state, because this seems to have fixed it:


Disable all Google calendar accounts (Calendar.app -> Preferences... -> Accounts).
Wait for the CalendarAgent process to subside. Eventually it will; use Activity Monitor to check. A reboot may help at this point.
Enable each Google calendar account, one by one: every time one gets enabled, the CalendarAgent process will get excited for a while. Wait for it to idle before enabling the next account.