PSA for #AsahiLinux users: Do NOT upgrade to macOS 27 Golden Gate!
Apple has changed how the boot picker and Startup Disk applications detect valid OS boot volumes. When using either from macOS 27, your Asahi partition will not be visible! We believe this to be a bug, and have filed a report (FB22994760).
If you have already upgraded to the beta and noticed that your Asahi partition has disappeared, do not stress. Your Asahi partition is still there, and you have not lost any data.
If you have already upgraded to macOS 27 and have a secondary installation of macOS 26 or below, set this as your default Startup Disk to restore access to Asahi. The Apple Silicon boot picker is a full-fat macOS app running in the default boot volume's recovery environment, so its behaviour is dependent on the default boot volume's macOS version.
If you insist on trying out macOS 27 as soon as possible, please ensure you install a secondary copy of macOS 26 first, or install macOS 27 itself on a secondary volume. We will not support users who have installed the macOS 27 beta without making contingency or rollback plans (such as ensuring at least one stable macOS version is installed).
We have patched the Asahi Installer to prevent it from running on macOS 27 until we have some idea of what's going on. It will print a version of this message and then exit if you try to run it from the macOS 27 beta.



