After a rollout in production, we've seen increased rate of failures in builds done with Xcode 27 RC1. We reverted the release and degradation is resolved. The root cause seems to be that there is a behavioral change in the new Xcode 27 version and our integration tests were using a different beta version, which passed all the tests. Since then, the behavior change is accommodated and rolled out without any issues.

After a rollout in production, we've seen increased rate of failures in builds done with Xcode 27 RC1. We reverted the release and degradation is resolved. The root cause seems to be that there is a behavioral change in the new Xcode 27 version and our integration tests were using a different beta version, which passed all the tests. Since then, the behavior change is accommodated and rolled out without any issues.