Oddities and more info
iCloud Drive works quite differently from other storage systems. Although Cirrus shouldn’t crash as a result of its quirks, it is easy to become confused by iCloud’s behaviour. Normally, when working with files and folders, if you can see them in a dialog, they exist and can be opened and used. This is not the case with iCloud Drive.
For example, if you try to open an item which has been evicted in a normal Files and Folders window, one of two things will happen: you may simply see an error alert reporting that an item with a slightly different name doesn’t exist so cannot be opened, or they may be a long pause, during which macOS downloads the item automatically, then suddenly displays the item as if nothing had happened.
If you open a downloaded item, and leave its document window open, you cannot evict it, as macOS recognises that the local copy of that file is open, so it cannot be removed from local storage.
If you open a downloaded folder in your iCloud Drive, then close that folder and evict it, you will be unable to open it again using the Open… menu command until it has been downloaded again, but you should still be able to open it from the Open Recent… command. It will then show that it is not downloaded, and the Downloading bar will be empty. You can check these out in better detail in an iCloud Browser window.
To observe how macOS works with stub and real files, open an iCloud Browser window and navigate to a folder in your iCloud Drive. Try downloading or evicting some files there, then click on the Refresh button in the browser window to see how they have changed.
More information about iCloud and how to understand the logs is at the Eclectic Light Company blog .
The Eclectic Light Company – https://eclecticlight.co