Like @vade above, trying to instrument a macOS app fails for me with the following unhelpful error message: Failed to start the recording: Failed starting ktrace session. Reading the comments above about iOS requiring iOS 26 to run the SwiftUI instrument, I’m now assuming that the same applies to macOS (I’m on 15.7.2). It would save everybody some confusion and time if it was made clear in Instruments that the SwiftUI instrument is not available for pre-26 targets. Ideally, disabling the SwiftUI instrument in the selection panel and having a help tip pop-up when hovering over it explaining that it requires 26 or later.

Still not implemented with the new developer forums this year. I, also, posted a feedback: FB14074932 Thanks.

I’d much rather see Apple’s developer support resources put into improving and supporting these forums. Besides, the less people use “X”, the better.