We've got an in-house Swift macOS desktop app with a FileProvider extension, which has been working fine on various machines up through Sonoma (and still does). We've just installed it on a Sequoia machine, and on it the FileProvider extension has lost the ability to access the shared app group. It can neither log to the Group Containers folder under ~/Library, nor access the pipe to the main app.
The group name is formatted as group.XXXXXXXXXX.com.orgname.appname in both targets. I'm not sure why it combines the iOS and macOS conventions, with both the group prefix and the teamIdentifier one -- it was first built some time before the point in 2025 when macOS supported iOS-style groups -- but again, it's been working.
For the record, The provisioning profile for EMPFileProvider has the App Groups capability enabled, and the App Groups capability is present in both build targets in Xcode. The existing group identifier is registered on the website; I've also manually registered the team-ID-less group name, so I can migrate.
The question is, is this actually the right approach? Will such a change break the app on pre-Sequoia machines? And if I proceed, what do I need to do to complete the migration? The app was built back in Xcode 12.5; will I need to update the entire build environment to take advantage of Xcode 16.3's explicit support for iOS-style group names, or can I get away with it since I've manually registered the new group?