It keeps asking if I want to run the app after building it. I reply yes, and then it says it can't do that, tries to build again by command line and gets stuck... (even with approving the command)

I am already using Claude in Xcode 26.2. What did they change / add specifically in 26.3? It's not super clear behind the marketing haze.

I don't think I'm ready for my phone apps to get even more sloppy...

I wonder if they used this internally to write iOS 26? Would explain some things...

One thing that would be genuinely useful would be the ability to integrate Claude with the Metal debugger somehow, to get automated analysis of GPU profiling. The .gputrace format is proprietary and cannot be easily analyzed, and it seems that the new "agentic coding" integration in Xcode also does nothing to expose this data to LLMs. Oh well.

Just in time for AI to go all tits up.

Wait…

https://xcodereleases.com hasn’t shown anything since last December, so I assumed Apple had taken a breather from Xcode development, but they released an RC build today?

Anyway, the Swift version seems unchanged (6.2.3), so is this update mainly for the so-called “Coding Intelligence” features?

In any case, Xcode isn’t my favorite IDE—it’s too slow and feels quite different from other major IDEs—so I probably won’t use it for day-to-day coding (though it’s fine for building and debugging).

My experience with AI with its predecessor, Xcode 26.2, was _really_ bad. One bug made it objectively unusable, and there were lots of fun issues/huge functionality gaps on top of that. Apple doesn't really seem to "get" agent-based coding, but I'm curious to see the results of other braver souls with 26.3.

I'm looking forward to trying the SwiftUI preview integration, though from my experience using the xcodebuildmcp and axe tools to let agents run simulators and capture screenshots, expectations will be low. It seemed like the models were capable of identifying issues like "button that should be there is not displayed", but not identifying when the layout is wrong or some element is too big.

Okay, this is going to help somewhat. But what I wish I had was command-line access to everything in a reliable way. Developing for iOS I frequently end up with imperfect debugging information exposed to a Claude Code etc. agent. I'll try to get this today and see.

This is huge news. Human-in-the-loop development is essential for actual software velocity gains. The current tooling around agent enabled iOS dev leaves a lot to be desired. Every time I work on web-dev tasks I'm jealous of the tooling.