Open Radar

 
Summary:
Once Apple stops signing an iOS release it can no longer be installed on devices. This is great for security and encourages users to stay on the most recent iOS version but it has a drawback for developers.

I foolishly, I admit, updated all of my iPhones to iOS 12 after our app passed our initial bug testing period on iOS 12.

Unfortunately, we recently ran into an issue which seemed to be a bug on iOS 12 and we no longer had the ability to verify that it ran correctly on iOS 11 before submitting a bug report. 

This particular bug only showed up after running on device for an extended period of time and necessitated being tested on device not the simulator. Details of this particular bug can be found at rdar://47382368 (http://openradar.appspot.com/radar?id=5046501151604736)

It would be very nice if there was a special profile registered Apple Devs could install on device to allow them to re-install older iOS versions.

This is definitely something to be approached with caution as there are a number of valid reasons to not allow users to install older iOS versions: limiting jailbreaks, security, etc.

But I am confident that a solution to this problem could be solved by Apple.

Steps to Reproduce:
Try to downgrade to iOS 11.x.

Expected Results:
A registered Apple developer could install a special entitlement that would allow them to downgrade to a prior iOS version. Perhaps only the last released major version of iOS (11.4.1 in this case) and possibly limited in some way.

Actual Results:
It is not possible, as all versions of iOS 11 are no longer being signed.

Version:
Any

Notes: