You may have noticed that fewer simulator pairs (iPhone + Watch simulator pairs) are baked into Bitrise stacks beginning with Xcode 26.4. This is due to a corner case involving Xcode and Apple’s virtualization framework in which the result of xcrun simctl pair commands are not persisting across virtual machine restarts.
If you have come to rely on the default simulator pairs that we have been providing for several Xcode stack versions, fear not. We have published the Simulator Device Pair step to provide a convenient way to define and create your own pairs directly in your workflow.
If you have any questions, we will be happy to answer them here.