A couple of weeks ago, I extolled the virtues of document versions, as built into macOS over the last 13 years. One situation you might expect them to be most valuable is when working on documents shared using iCloud Drive: edit a document using one Mac or device, then work on it again using another Mac or device, and iCloud Drive then shares all those versions across your Macs and devices. Although iCloud Drive does support versions, they don’t work that way. Allow me to illustrate this with a short demonstration.

In this case, I’ve been working on the ReadMe file for Skint, although you can repeat this using any other app that can read and write documents in iCloud Drive, such as Pages. On my iMac Pro, I’ve built up a total of ten versions plus the current one, starting from the first short version of a mere 7,031 bytes, and ending with the current one of 11,206 bytes.

Those are listed here using Revisionist, and fully accessible to the Rich Text editor I’m using on the iMac.

When I open that same document on my Mac Studio, all it can see is the current version.

On the Studio, I then progressively undo all my previous work, shortening the text down until it only occupies 1,925 bytes. On that Mac, Revisionist shows the original version and five new ones, plus the current version, now a shadow of its former self.

I then switch back to the iMac, and all Revisionist or my Rich Text editor can see there are the ten previous versions saved on that iMac, and the last of those saved by the Studio.

If I had done the same editing on an external drive that I switched between the two Macs, both would have had full access to every one of that document’s fifteen previous versions, plus the current document.

This is because document versions are saved to local storage on the same volume as that document. When the volume moves between Macs, all its versions move with it. When different Macs and devices access that document in iCloud Drive, their versions remain local, and aren’t shared in the way that the document is.

There’s an interesting side-story here. As you can imagine, the hidden version database stored in each volume can grow large, complex, and full of many small files. During the Catalina cycle in early 2020, that hidden folder started to bring many Time Machine backups to their knees. The mystery here was why Time Machine had ever tried to back up the version database, because it was never restored in a volume restore, as its structure and contents make restoring versions impossible. Late versions of Time Machine thus added the version database to the system exclusion list and restored performance, fixing a bug that had taken 13 years to come to fruition.

I have long considered the handling of document versions by iCloud Drive to be inadequate for anyone sharing their work and making use of versions. I first reported this here almost exactly six years ago, in my initial account of versions in macOS. Later that year, the sharing of versions in iCloud Drive started, but was patchy and unreliable. By Mojave, documents in iCloud Drive were saving versions in a frenzy. Then last year I noticed that had finally been abandoned in favour of the present scheme.

If you use Apple’s apps like Pages and Numbers, or others that make use of the version system built into macOS since OS X 10.7 Lion in 2011, then be aware that those versions can’t be shared across iCloud, introduced in the same year. Over those 13 years, support for shared versions has gone from none to the frenzy of Mojave, then returned full circle back to none again. Can it really be that difficult to get right?