How to fix GRUB after a SteamOS update

My partner just ran into an issue after updating his SteamDeck to the latest SteamOS version (3.4.x to 3.5.7). He has a dual boot setup running using rEFInd, and while that survived the OS update just fine, when he wanted to return to SteamOS after a quick stint in Windows today, he was greeted by a GRUB boot menu. Detective foosel to the rescue. Attempting to boot the SteamOS entry in grub resulted in an error like this (with another device UUID):...

November 25, 2023 · 2 min