SUMMARYThe Asahi Linux team warned Apple Silicon users not to install the macOS 27 beta because changes to the boot picker and Startup Disk app can hide Asahi partitions and block Linux from booting. The team updated its installer to stop installs on macOS 27 for now and advised users to keep a stable macOS copy on a secondary volume. Users who already upgraded have not lost data, and the Asahi partition remains on disk.
The Asahi Linux team is warning Apple Silicon users not to upgrade to the macOS 27 beta because Apple's changes to the boot picker and Startup Disk app make Asahi partitions invisible, preventing Linux from booting. The Register reports: The team added: "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." They've also updated the installer to prevent installs from running on macOS 27 for now. For anyone who ignored all of the above, "we will not support users who have installed the macOS 27 beta without ensuring at least one stable version of macOS is installed."
Considering macOS 27 is in beta, the issue may be accidental rather than an attempt by Apple to block Linux on its hardware. The Asahi team said it has filed bug report. The good news for anyone who pulled the trigger on installing the macOS 27 beta is that although the partition might not be visible, it hasn't gone anywhere. The Asahi team wrote: "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."