Xcode 12.1 cannot install to iOS 14.2

After the macOS 10.15.7 update, Xcode showed "Install Additional Components", so I did that.

Now I find that Xcode can't install to iOS 14.2
It says:
"{phone} is not available. Please reconnect the device."

Tried:
  • Disconnect/reconnect

  • Restart (all devices)

  • Different phone (also iOS 14.2)

  • "Empty the Derived Data" folder

I know there is a downloadable Xcode 12.2RC, but I prefer to stick to the App Store version on my main Mac.
Apple say: “The term “Release Candidate” (RC) replaces “GM seed” and indicates this version is near final.”
"Near" final?!

Is there a timing SNAFU here?
Surely the release versions should all line up, and work together!
Should Xcode 12.2 be available on the App Store, to go with iOS 14.2?
Answered by robnotyou in 646043022
Xcode 12.2 is now available on the App Store.

Apple didn't reply to my Feedback Assistant submission, perhaps preferring to run out the clock.
After an awkward 6 days, this issue is now resolved.

Until next time...?
Same problem, I'm downloading the beta, it should work
The "Release Candidate" should work...
...but it seems wrong that there's an iOS version released, without a compatible Xcode in the App Store (if that is the case).
I have the same problem too.
Same problem here!
I reported this issue to Apple, using Feedback Assistant.
This is currently showing "Recent Similar Reports: None".

So I would encourage anyone else who is experiencing this issue, to report it to Apple!

(That might not help us with this specific issue, but next time...)
I have the same problem. I hope I don't have to go to Beta software.
I have the same issue. I'm sure it's not intentional.
Same issue with XCode 12.2 beta 4 (12B5044c), iOS 14.2.
I have the same problem!
Same issue, can't use Beta version as on production track and too risky.

Come on Apple sort this out asap
After many tries going back and forth between Xcode 12.1 and Xcode 12.2 beta 4 (the Release Candidate), I got both now to install and launch my app. However, it then gets stuck at the launch screen. The app does not start running, no debugging session is started, the console stays empty.

The app does get installed. When I stop the session, I can actually run the app stand-alone on the 14.2 device.

No iOS betas seem to be available at this time, and going back to 14.1 is not allowed.

Questions:
  • Is there any version of Xcode that can debug apps on iOS 14.2 devices?

  • Do I need to stop development until Apple deigns to release Xcode 12.2?


I would recommend you getting used to having several Xcode versions installed in parallel by downloading and installing the manually instead of using the Mac App Store solution. You will often find yourself in a situation where you might want to use some Xcode version over the other for various reasons. Many developers are doing this for years and it is fortunately straight-forward:
  1. Login to developer.apple.com

  2. Navigate to Account -> Downloads -> More

  3. Download the Xcode version(s) you need (maybe even some ancient ones).

  4. After download completed click on the .xip file to uncompress it.

  5. Rename the app bundle(s) so you can distinguish them by version (e.g. "Xcode.app" -> "Xcode12.2rc.app").

  6. Move the renamed Xcode app bundle(s) To Applications.

That way you can launch whatever Xcode version you need at any time.

In some rare cases you might want to run an older Xcode version with an iOS device running a bleeding edge iOS version officially not supported by the older Xcode version. In this case you can often just copy the respective directories from Xcode
whatever.app/Contents/Developer/Platforms/iPhoneOS/DeviceSupport/ over to your older Xcode version's app bundle.

I would recommend you getting used to having several Xcode versions installed in parallel...

That is an interesting idea, but...

My worry is that the different versions of Xcode don't exist in isolation.
Xcode creates various files outside it's own app package.
So how can I be sure that this wouldn't introduce some subtle change in operation?
Xcode "a" might be accessing a file created by Xcode "b", which is different in some way.

I might risk it on a secondary machine, but my main Dev machine stays pristine - App Store versions only, no Betas or multiple versions!
Follow this simple steps and run/debug on iOS 14.2 with Xcode 12.1
https://github.com/filsv/iPhoneOSDeviceSupport

Thank me later :D
Here is my solution:
  1. Install the Xcode 12.2 release candidate. Don't worry about renaming as suggested by CrudeByte, it will install as Xcode-beta.app in parallel to your Xcode.app. It will install "additional components", though.

  2. Remove the contents of ~/Library/Developer/Xcode/iOS DeviceSupport (or at least the folders starting with 14.2)

  3. Build and run your app in Xcode-beta (12.2 beta 4, also known as release candidate). This might take a few minutes as Xcode copies caches from your 14.2 device to the device support folder

  4. You may want to continue in Xcode-beta or return to Xcode 12.1. Either will now build, run, and debug your app in reasonable time.

I understand your concerns about installing a beta, as I did have issues with switching back and forth between beta and release versions of Xcode a few times in the past. This time around it seems to work. I would still not recommend to run them at the same time.

tundaware's answer on another thread inspired this. If you don't want to install a beta but can stomach replacing parts of your Xcode installation with material downloaded from GitHub, aaronsarkissian's answer should help as well, at it is based on the same idea.


Xcode 12.1 cannot install to iOS 14.2
 
 
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