Xcode 15.2 requiring iOS 17.2 but won't install it on an Intel based iMac

I did try that. From Xcode 15.2, trying to download and install iOS 17.2 support using Settings/Platforms fails to install on my Intel based iMac. As soon as I attempt it, Xcode will no longer render the storyboard or build the app. Would I be correct to interpret your first sentence as requiring that the minimum target environment for an iPhone app is iOS 17 as of April 2024? Since Xcode 15.2 won't support that (contrary to the documentation) and newer version(s) of Xcode won't run on Intel based Mac's either, that would imply that my choices are to buy a new iMac or abandon support of my patient safety app in the App Store. Am I interpreting that correctly or am I missing something? Until I hear back, I will try to complete the app upgrade targeting a minimum of 16.0 and try to upload the new app release to the App Store and see what happens. Thanks for your feedback.

Update: I tried dropping back to Xcode 14.3.1. It told me the project couldn't be opened because it was in a future file format. It recommended using a future version of Xcode to save the project in a format compatible with 14.3.1 so I reinstalled 15.2 expecting to look for a way to create a past file format. To my surprise, when I opened my project in 15.2, it worked. After some time, the main storyboard rendered and it no longer requested iOS 17.2. I don't know why this worked but hopefully the knowledge will help someone else that is stuck. I just hope Xcode keeps working long enough for me to write the software upgrade for my app.

I purchased a refurbished Retina 4K, 21.5 in., 2017 from Apple (3.4 GHz Quad Core Intel I5) without considering how quickly it would "sunset" (my bad). At this point, Xcode 15.2 is still working and I am continuing to work on the app upgrade. Settings/Platforms now show an iOS 17.2 on disk (not the simulator) so I may be OK. I am not going to plugin my iPhone (17.4) in developer mode or download an iOS 17+ simulator until I complete the upgrade and try to upload it to the App Store. (I suspect plugging in my iPhone may be what caused the collapse of the first copy of 15.2). Given that I appear to have some type of iOS 17.2 support on the current copy of Xcode 15.2, I am optimistic that the app will be accepted. After that I will "save my pennies, nickels and dimes" for a new iMac.

Re your other comment, a 2017 iMac can't go past Ventura 13.6.6 whereas your 2019 can. My days are numbered.

Thanks again for your help.

Final update: It did in fact work out. Xcode 15.2 built a new version of the app that was successfully uploaded and accepted into the App Store. I subsequently was also able to simulate an iOS 17.2 iPhone with that app (using Xcode 15.2). I also downloaded the app to my iOS 17.4 iPhone from the App Store and it appears to work properly.

Summary: Attempting to use a device or simulator above 17.2 appears to cause Xcode 15.2 to get caught in a "Catch-22" asking you to download a higher version of iOS 17 than it is willing to install. You can't build the app or even render a storyboard until the problem is resolved. This may not be the only solution but in my case I did the following:

1) Delete Xcode 15.2 from the applications folder,

2) Go to the developer support site and download Xcode 14.3.

3) Attempt to read the app you have been working on in 15.2 using 14.3. (This will fail because the file format has already been upgraded but it appears to reset something in the project file.)

4) Rename 14.3 then re-install 15.2. (I haven't done it yet but I am assuming you can delete the renamed version of 14.3 at this point.)

5) Xcode 15.2 should now read the project without requesting an upgrade. You should be able to complete your build as long as you don't ask it to download a version of iOS 17 that it can't support.

Best of luck to one and all.