I currently have Xcode 4.1 installed. I attempted to update using the App Store so that I can test my app in iOS 5. The update program downloaded properly, and it took quite a while to perform the update, whereupon Xcode relaunched.
I couldn't find iOS 5 in the deployment target list, and I checked the "About" section, and found that I was still using Xcode 4.1, build 4B110, not Xcode 4.2, build 4D199, as described on the download Xcode 4.2 page.
I ran the update again, without any luck. I attempted to download the update again from the app store, but it just has a blue button saying "installed", and no obvious way to force a reinstall. The page on the app store clearly says Xcode 4.2, so that is what I would expect to have by now.
Has anyone run into the same issue? After quite a bit of googling, it would appear that this is not the case. I would be interested to hear any hypotheses, or solutions.
Move your /Developer directory to something like /Developer-4.1, then install Xcode 4.2 again using /Developer as the install path. After the install, inside /Developer/Applications/ should be the new Xcode 4.2 that you want to use.
[ 16:44 Jonathan@MacBookPro / ]$ sudo mv /Developer /Developer-4.1
This is how my / looks like from all the different versions:
[ 16:44 Jonathan@MacBookPro / ]$ ll
drwxrwxr-x+ 46 root admin 1.5K Oct 12 11:52 Applications
drwxrwxr-x 15 root admin 510B Sep 20 13:27 Developer
drwxrwxr-x@ 17 root admin 578B Sep 20 13:12 Developer-3.2.4
drwxr-xr-x@ 10 root admin 340B Sep 20 13:54 Developer-3.2.5
drwxrwxr-x@ 16 root admin 544B Oct 8 14:23 Developer-4.2
drwxrwxr-x@ 18 root admin 612B Sep 20 13:44 Developer-4.2-beta7