TL;DR: Still open - see below.
This morning I woke up to some not-so-nice surprise - my 2018 MPB 13" would be kind of totally unusable. The accountsd process was stable at 400%, battery was going like ice-cream in the Sahara, and opening up LibreOffice was like a major achievement.
I did check the logs (that were growing at like 500 lines per second) and I saw a lot of lines at FAULT level:
fault 07:54:04.271342+0200 accountsd Unentitled access by client 'CallHistoryPlugi' (selector: accountsWithAccountType:handler:)
fault 07:54:05.685220+0200 accountsd Unentitled access by client 'com.apple.siri.e' (selector: accountsWithAccountType:handler:)
fault 07:54:32.545747+0200 accountsd Unentitled access by client 'CallHistoryPlugi' (selector: accountsWithAccountType:handler:)
fault 07:54:50.155679+0200 accountsd Unentitled access by client 'com.apple.siri.e' (selector: accountsWithAccountType:handler:)
fault 07:54:52.977307+0200 accountsd Unentitled access by client 'CallHistoryPlugi' (selector: accountsWithAccountType:handler:)
fault 07:55:23.636667+0200 accountsd Unentitled access by client 'com.apple.siri.e' (selector: accountsWithAccountType:handler:)
fault 07:55:23.636893+0200 accountsd Unentitled access by client 'CallHistoryPlugi' (selector: accountsWithAccountType:handler:)
fault 07:55:26.732481+0200 accountsd Unentitled access by client 'AddressBookManag' (selector: accountsWithAccountType:handler:)
To make a long story short, I looked at the full log where there was:
default 08:50:35.352204+0200 accountsd [com.apple.calendar.accounts.notification] [Account ***MY@APPLEID**** (....) should have child account]
default 08:50:35.352243+0200 accountsd [com.apple.calendar.accounts.notification] [Nope we don't need to process ***MY@APPLEID**** (....)]
default 08:50:35.354888+0200 accountsd AMSAccountNotificationPlugin: [6590CE3B] Handling account:didChange. changeType = <ACAccount: 0x...... type = iTunesStore | backingID = .... | username = ***MY@APPLEID**** | altDSID = ... | DSID = ... | active = appstore; itunes | storefront = itunes:...,42; appstore:...,13> | account = kACAccountChangeTypeModified | caller = commerce
default 08:50:35.355123+0200 accountsd didChangeWithType: Is active: 1 (<private>)
default 08:50:35.355161+0200 accountsd Should process: 0 (<private>)
default 08:50:35.356436+0200 commerce "Completed account save: YES - (null)."
default 08:50:35.356791+0200 accountsd AMSAccountNotificationPlugin: [6F7C9447] Finished processing account:didChange:.
default 08:50:35.356878+0200 accountsd AMSAccountNotificationPlugin: [6590CE3B] Processing the change .
error 08:50:35.356925+0200 accountsd AMSAccountStoreCache: [6590CE3B] An ACAccountStore has no associated media type. Returning the default media type for the current process. accountStore = AMSAccountStoreCache | defaultMediaType = com.apple.AppleMediaServices.accountmediatype.itunes
error 08:50:35.357013+0200 accountsd AMSAccountStoreCache: [6590CE3B] An ACAccountStore has no associated media type. Returning the default media type for the current process. accountStore = AMSAccountStoreCache | defaultMediaType = com.apple.AppleMediaServices.accountmediatype.itunes
error 08:50:35.357296+0200 accountsd ACAccount: [6590CE3B] Failed to decrypt an account property. key = accountFlags | value = {
So I did go to system preferences -> Apple ID and removed my AppleID. I then added it back in, and everything went back to normal. Thanks Apple for three hours down the drain on a Sunday morning.
I am posting it here so if somebody else has the same issue, at least they can Google it.
I am not sure if this is related to Catalina 10.15.7 - I updated yesterday, so the coincidence is pretty suspicious.
Looks like the problem is back. I am now trying to stay logged off of Apple ID for now and see if this keeps the problem at bay. I cannot afford to use my Mac as an expensive fridge magnet and have work to do on it.
I'ts been a week, and still there is no definite workaround. From the many comments below, it looks like the only thing that actually works (and worked for me) is to be signed off of my Apple account. Yes, this allows me to work, but I'd say it's less than optimal. Deleting my Internet accounts and whatnot.... I need them. You know, the very reason I have a Mac is to have a hassle-free PC experience, where things just work and I can do billable activities instead of recompiling drivers.
Personally, I would not delete system databases that I'm not 100% sure what they are for, but YMMV.
Anybody knows if there is a filed bug in Apple for this issue? or how one is supposed to file one?
Apple Support contacted me on Twitter; I posted the issue and a link to this discussion and we'll see if there is an official suggestion/feedback/bug number.
So far issue seems to be solved for me