Testing iPhone Duo with Xcode 27.1 beta
A practical simulator checklist for adaptive layouts, Duo poses and clear test evidence, updated after the SDK release.
The Duo simulator is available in beta
Apple released Xcode 27.1 beta with iPhone Duo SDK and simulator support on September 18, 2026. Install it on a Mac running macOS Tahoe 26.6 or later, then confirm the iPhone Duo destination and runtime are actually installed. DuoReady does not host a simulator; importing a result is separate from executing a test.
Useful now: remove assumptions
Review fixed widths, global screen dimensions, device-identity layout branches and safe-area overrides. Our static analyzer flags these patterns without executing source. Use the sample report to see both a deliberate finding and its revised code. Intentional patterns can be false positives.
Build a reproducible first pass
Use your existing Xcode UI-test target to exercise a real journey on the Duo destination. Record Xcode build, iOS runtime, app commit, starting pose, expected behavior and result. Check a draft through outer/inner display transitions, rotation, keyboard presentation, large text and scene changes where supported. Capture failures and skipped cases rather than calling an unasserted screenshot a pass.
Know the beta limits
Apple lists initial launch delays, unavailable StandBy and unavailable running/debugging for most app extensions in the Duo Simulator runtime. These limits can block a scenario without proving an app defect. Physical camera optics, thermal behavior and other hardware-dependent results still need device evidence. A static scan does not establish a simulator pass.
Sources and limits
Our calculations and proposed test steps are independent analysis. Follow the original documentation for SDK-specific behavior.