Xcode 26.6 immediately terminates with SIGKILL (Code Signature Invalid) during SDK initialization on Apple Silicon (M4)

Question

zwei1189 OP

Created Jul ’26

Replies 1

Boosts 0

Participants 2

I'm experiencing a reproducible issue that completely blocks Xcode on an Apple Silicon Mac.

Environment

• MacBook Air (M4) • macOS 26.5.2 (25F84) • Xcode 26.6 (17F113) • Also reproduced with Xcode 26.5 (17F42)

Issue

Xcode terminates immediately before the main window appears.

Instruments also terminates immediately.

The command:

xcodebuild -version

works normally.

However, any command that requires SDK initialization immediately terminates, for example:

xcodebuild -showsdks

The process is killed instantly.

Crash reports consistently show:

SIGKILL (Code Signature Invalid) Termination Reason: Namespace CODESIGNING, Code 2, Invalid Page

The crash occurs during dyld page authentication:

dyld4::fixupPageAuth64()

What I have already tried

• Reinstalled Xcode • Reinstalled macOS • Reinstalled Command Line Tools • Reinstalled Rosetta • Tested in Safe Mode • Tested with a newly created macOS user • Removed caches and DerivedData • Verified Xcode signatures

The behavior is identical in every case.

Interestingly, xcodebuild -version succeeds, but every SDK-related command is killed immediately, suggesting the failure occurs during SDK/framework initialization rather than Xcode startup itself.

I have already submitted:

Feedback Assistant: FB23586800

DTS Case: 20879405

Has anyone else seen the same issue on Apple Silicon (especially M4)?

Any known workaround or confirmation that this may be a macOS 26.5.x / Xcode 26.5–26.6 regression would be greatly appreciated.

Answer 1

DTS Engineer OP

Apple

Jul ’26

Thanks for your post! It seems like you’ve already asked about this at code-level support, where you received some helpful answers. Now, you’ve also submitted a bug report and a forum post as well.

We value your questions! I always suggest starting with a forum post, as most engineers are here and ready to assist. Code-level support TSI is best used when you need to share information that requires privacy, and it’s best to move to a bug report once the issue has been identified by the correct engineering team to provide a fix. Trying to do all three at once might cause some problems, as it would involve three different teams, and someone would need to coordinate their efforts and find a way to support you on the best way possible.

In that regard, it appears that your bug has been forwarded to the appropriate team, who are actively investigating its nature. We kindly request that you allow them sufficient time to address the issue and provide you with a resolution through the Feedback Assistant. Once they have completed their review, we will proceed accordingly.

You can see the status of your feedback in Feedback Assistant. There, you can track if the report is still being investigated, has a potential identifiable fix, or has been resolved in another way. The status appears beside the label "Resolution." We're unable to share any updates on specific reports on the forums.

For more details on when you'll see updates to your report, please see What to expect after submission.

Albert  WWDR