Find and copy Xcode device support files
Every once in a while I run into a situation where I update my iPhone to the latest iOS before I realize I'm still using an older version of Xcode for some projects. I usually realize this when Xcode tells me that it "Could not locate device support files". I'm sure many folks run into this problem.
Luckily, we can fix this by copying the device support files from the new Xcode over to the old Xcode, or by grabbing the device support files from an external source.
Copying device support files if you already have the latest Xcode installed
If you have the latest Xcode installed but need to use an older Xcode version to work on a specific project, you can safely copy the device support files from the new Xcode over to the old.
This can be done using the following command in your terminal:
cp -R /Applications/<new xcode>/Contents/Developer/Platforms/iPhoneOS.platform/DeviceSupport/<target ios> /Applications/<old xcode>/Contents/Developer/Platforms/iPhoneOS.platform/DeviceSupport/<target ios>
Make sure to replace
<new xcode> with the path to your latest Xcode app,
<old xcode> with your old Xcode app and
<target ios> with the iOS version you wish to copy device support files for.
I use xcversion to manage my Xcode installs. Read more in my post about having more than one Xcode version installed.
So for example, to copy device support files for iOS 13.4 from Xcode 11.4 to Xcode 11.3.1 you'd run the following command:
cp -R /Applications/Xcode-11.4.app/Contents/Developer/Platforms/iPhoneOS.platform/DeviceSupport/13.4 /Applications/Xcode-11.3.1.app/Contents/Developer/Platforms/iPhoneOS.platform/DeviceSupport/13.4
Let's look at the same command, formatted a little nicer:
cp -R \ /Applications/Xcode-11.4.app/Contents/Developer/Platforms/iPhoneOS.platform/DeviceSupport/13.4 \ /Applications/Xcode-11.3.1.app/Contents/Developer/Platforms/iPhoneOS.platform/DeviceSupport/13.4
Both of the above snippets copy iOS 13.4 support files from Xcode 11.4 to 11.3.1. After doing this, reboot Xcode (I always do just to be sure) and you should be able to run your Xcode 11.3.1 project on devices running iOS 13.4.
As an alternative to copying the files, you can also link them using the
ln -s command in your terminal:
ln -s \ /Applications/Xcode-11.4.app/Contents/Developer/Platforms/iPhoneOS.platform/DeviceSupport/13.4 \ /Applications/Xcode-11.3.1.app/Contents/Developer/Platforms/iPhoneOS.platform/DeviceSupport/13.4
This command creates a symbolic link to the device support files instead of copying them. Both commands achieve the same result and are equally effective.
Obtaining device support files if you don't have the latest Xcode installed
Not everybody who needs device support files will have the latest Xcode available. If this is the case, I recommend that you take a look at this repository. It collects device support files for all iOS versions so you can clone that repository and copy, or link, device support files from that repository to the Xcode version you're using. You can use similar command to those that I showed in the previous section except you'd replace the old Xcode path with the path to the appropriate device support files in the clones repo.