In another thread a fellow user suggested installing the beta 5 on a machine with beta 6 to recover from the Xcode/beta 6 fiasco. Can you go back to any beta as long as you've installed all the subsequent ones before it?
How do the delta updates work?
Hi,
The way it works is that the only full installer for 10.11 is Beta 1 (~6.5GB).
Betas 2 through to 6 are what are called deltas, incremental updates (~1.2 to 2.0 GB in size) that simply add to and change what already exists.
So you can only start with Beta 1 (a.k.a. Developer Preview 1) and then update through Beta 2, then 3, then 4, then 5 and finally 6.
To go back to an earlier by reinstalling it directly from links is not ideal - for instance Beta 6 knows about all the changes the betas before it made and is programmed to make some improvements based on that. Installing Beta 5 back for all intents and purposes reverts things back to how they were before Beta 6, but there may still be some changes that are not "un-made" because Beta 5 expects to be installed over Beta 4 - it has no knowledge of Beta 6. That's not necessarily going to cause any problems, but the possibility that it could cause unexpected issues is there nonetheless.
However the Xcode failiure in Beta 6 is such an extreme circumstance, that these concerns seem minor compared to the ability to get back to work without having to reinstall all the betas from scratch and remigrating your data back afterwards.
When people started discussing where to get the links from non-Apple domains to install Beta 5 over Beta 6, I decided that it would be better I post those that download directly from Apple's CDN.
Max.
I make a time machine backup just before and just after I install each beta. That way if things go awry with the latest beta I can do a time machine restore back to any previous beta.