What happens
Since installing macOS 27.2 b2 (didn't go through b1, might have been there already), the Contacts app has become almost unusable on my two Macs. Opening a contact or moving to the next one often freezes the app for 8 to 10 seconds, with the spinning wheel. It happens many times in a row while browsing the address book.
It comes back no matter what I try: restarting, letting iCloud resync the contacts, deleting and recreating cards. Once, it seemed to go away for a couple of minutes upon restarting, but it returned.
Both Macs share the same iCloud account (~690 contacts): a MacBook Pro M4 Pro and a Mac mini M4, both on 27.2 b2 (26B5091g). Reported as FB24928119.
Technical details
- All 18 Contacts_*.spin reports show the main thread blocked in CNCDContactFetcher withLockedContext_fetchPosterData, waiting on a synchronous XPC call to com.apple.contacts.poster.api. That service is postersyncd, which syncs Contact Posters.
- The kernel kills postersyncd with exceeded mem limit: InactiveHard 20 MB (fatal) at 30–35 MB. launchd relaunches it every ~10 s: 74 kills in 26 h on one Mac, 54 in 24 h on the other.
- log stream --level debug shows the same sequence on every relaunch: START: Background cleanup → Potential cleanup for missingLocalContactIdentifiers → FetchingContacts → killed within the same second. The cleanup never finishes, so it restarts forever.
- The poster store (group.com.apple.contacts/ContactsMetadata) is ~85 MB, with blobs of up to 9 MB each. The memory limit stays InactiveHard even while Contacts is frontmost.
- Moving the poster store aside doesn't help: iCloud rebuilds it in ~25 s. Posters deleted from iOS or iCloud.com get a deletion date but are never purged.
Question: has anyone else seen this on 27.2 b2? Is there a way to reset the Contact Posters data stored in iCloud?
