I saw in the Xcode 16 release notes that on-device debugging is no longer available on watchOS prior to version 7.0, but I can't even get a signed, compiled app to run on an older watch. The current version I have live in the App Store works just fine on 4.3.2. I have changed no code, I just started building the app with Xcode 16, and now it won't launch on older watches.
Is it no longer possible to update an app for older watches?
I saw in the Xcode 16 release notes that on-device debugging is no longer available on watchOS prior to version 7.0
That is correct. To continue debugging pre-watchOS 7.0, you must use Xcode 15.4.
but I can't even get a signed, compiled app to run on an older watch.
When the minimum deployment target is watchOS 4.3.2, you can still launch your app. Please file a bug report using Feedback Assistant with a sysdiagnose file on the device to determine what issue you are encountering. Please post the Feedback number here once done.
https://download.developer.apple.com/iOS/watchOS_Logs/sysdiagnose_Logging_Instructions.pdf
I’m having trouble using these instructions to obtain a sysdiagnose file from the watch. Holding the crown and side button for 2 seconds doesn't appear to work in watchOS 4.3.2 or on this older watch model.
I see your note that apps that worked on watchOS 4 previously should launch just fine when compiled with the latest SDK. I should note that I am using the same exact source code as what's in the App Store right now. The only difference is the store version was built with Xcode 15 and the one that errors was built with Xcode 16. I can download the version I have in the App Store right now and it launches and functions as expected on watchOS 4.