https://developer.apple.com/documentation/macos-release-notes/macos-26_1-release-notes

macOS Tahoe 26.1 Beta 2 Release Notes

macOS Tahoe 26.1 Beta 3 Release Notes
Update your apps to use new features, and test your apps against API changes.
Overview
The macOS 26.1 SDK provides support to develop apps for Mac computers running Tahoe 26.1 beta 3. The SDK comes bundled with Xcode 26.1, available from the Mac App Store. For information on the compatibility requirements for Xcode 26.1, see Xcode 26.1 Release Notes.

Apple TV app
Resolved Issues
Fixed: In Apple TV app on macOS, the Search bar is missing. (159419539)

Background Assets
Resolved Issues
Fixed: AssetPackManager.url(for:) unexpectedly throws an error when looking up the URL for a locally available asset file. (157959878) (FB19512759)

Game Controller
Resolved Issues
Fixed: The time returned by GCPressedStateInput.lastPressedStateTimestamp is not in the correct time domain. (159124910)

Fixed: Game controller input might be delayed when many tasks are submitted to the default global concurrent queue. (159163570)

Fixed: Non-UI processes might not receive game controller input after setting GCController. shouldMonitorBackgroundEvents to true. (160974748) (FB20307654)

sudo
Known Issues
There are now added security checks when loading the /etc/sudoers configuration and /etc/sudoers.d folder. When the owner is not set to root, the configuration is ignored and sudo might not work. (155330149) (FB18698477)

Workaround: Change the files to proper owner using Recovery and chown 0:0 /etc/sudoers.

SwiftUI
Resolved Issues
Fixed: The navigationLinkIndicatorVisibility modifier crashes when run on iOS 17, iOS 18 and aligned releases.

You must recompile your app against the 26.1 SDK to receive this fix. (158236264) (FB19613386)