NSLog doesn't work on iOS 26 when the app is installed from TestFlight

I've noticed that NSLog() doesn't do anything on iOS 26 when an app is downloaded from TestFlight.

I've got an app uploaded with a liberal sprinkling of NSLog lines in it for debugging purposes - if I download that onto an iOS 18 devices, and use Apple Configurator's console or the Mac's console app, then the logging output is verbose and as expected. But if I download that same app onto an iOS 26 handset, there's nothing.

Logging is visible in the Xcode console, however sometimes there are situations where you need console logging with a TestFlight build.

What happened? Was this an intentional change? Why. This is a major hindrance in diagnosing issues / bugs etc.

Answered by DTS Engineer in 855809022
It doesn't occur when using OSLog, just NSLog.

Cool.

In that case the path forward here is clear: Move from NSLog to the system log API. Your Friend the System Log has lots of advice on that front, including a list of specific benefits for folks making this move.

Is this intentional?

That’s my understanding.

Share and Enjoy

Quinn “The Eskimo!” @ Developer Technical Support @ Apple
let myEmail = "eskimo" + "1" + "@" + "apple.com"

If you call the system log directly, rather than via the NSLog compatibility shim, do you see the same problem?

For links to documentation about the system log APIs, see Your Friend the System Log.

Share and Enjoy

Quinn “The Eskimo!” @ Developer Technical Support @ Apple
let myEmail = "eskimo" + "1" + "@" + "apple.com"

Hello It doesn't occur when using OSLog, just NSLog.

Is this intentional?

My apps can change over, of course, but there's a installed app base out there of millions of users (some users are savvy enough to be able to collect console logs if ever there's an issue they report)

It doesn't occur when using OSLog, just NSLog.

Cool.

In that case the path forward here is clear: Move from NSLog to the system log API. Your Friend the System Log has lots of advice on that front, including a list of specific benefits for folks making this move.

Is this intentional?

That’s my understanding.

Share and Enjoy

Quinn “The Eskimo!” @ Developer Technical Support @ Apple
let myEmail = "eskimo" + "1" + "@" + "apple.com"

NSLog doesn't work on iOS 26 when the app is installed from TestFlight
 
 
Q