Build failures Xcode 26.4.0

This incident has been resolved.

Customers running macOS jobs on m4pro.medium and m4pro.large with the xcode:26.4.0 image experienced job rejections with the error: "Job was rejected because resource class <class name>, image xcode:26.4.0 is not a valid resource class". The issue has been resolved and affected jobs should now run normally. Customers whose jobs failed may rerun affected jobs. We thank you for your patience while our team worked on implementing a fix.

A fix has been implemented and we are monitoring the results.

There are build failures for Xcode 26.4.0; we have identified the issue and are currently implementing a fix.