I want to install and try out the new features of macOS 10.12. Also I really want to work on Xcode 8.0. But the same time I have some client projects which should written on Swi
I have installed OS X Sierra and I was working with XCode 7.2. I found some alignment, issues when the XCode run in Sierra. I have reported to the bug reporting centre. I got reply from the apple team that XCode 7.x versions are not supported in OS X Sierra and all the bugs has been closed. They recommends XCode 8 in OSX 10.12.
Xcode 7.3.1 and Sierra is a non-supported configuration. While most of it will work, things like running a project on the simulator won't.
To keep Xcode 7.3.1 running again besides Xcode 8.2 on macOS Sierra 10.12.2 I had to clean the following folders:
~/Library/Developer/
~/Library/Application Support/Developer
~/Library/Application Support/Xcode
Even cleaning the userdata of the specific project was helpful:
projectname.xcodeproj/xcuserdata
projectname.xcworkspace/xcuserdata
After restarting the mac and trying to open the project it crashed again because there was already content in this folder:
~/Library/Application Support/Developer/Shared/Xcode/Plug-ins
After deleting these plug-ins again it finally worked!
You should also be aware that you need the current public releases of macOS (El Capitan) and Xcode (7.3) to create and submit archives to the iTunes App Store. Archives created with beta versions Xcode (8b1), or with the current Xcode 7.3 on a beta version of macOS (Sierra 10.12b1) won't be accepted (submission process fails). It's advised you backup your system before installing the macOS beta, and/or install the beta OS on a new partition. You can also install the current OS and Xcode on a small partition (10-20GB or so) if you'll need to make a submission in the next 3 months, and remove it when the public releases are available. It takes a little setup, tho, to configure your signing certs, etc.
You can absolutely install Xcode 7.3.1 on macOS Sierra alongside the beta version of Xcode 8.
If you are having issues running Xcode 7.3.x or running the simulator:
Reinstall Xcode 7.3.x from https://developer.apple.com/downloads/.
Manually attach the debugger to your process as outlined in this Stack Overflow answer.