The October security update for the Pixel 2 series is out! We’ll be using the factory images, with the help of TWRP to update our rooted phone, as well as being able to keep root access after updating!
TWRP (3.3.0-0) cannot mount the
/data partition while it is encrypted. You can attempt to remove your screen lock before booting TWRP. But I would recommend sideloading Magisk in TWRP via ADB Sideload so you don’t have to re-enroll your fingerprints and reconfigure your apps.
Sideloading in TWRP
From TWRP’s main menu, go to Advanced > ADB Sideload > Swipe to start Sideload.
Then use the ADB command:
adb sideload [insert path of zip you wish to sideload & flash]
We can use the latest stable version of Magisk (v20.0) which has been updated to support Android 10 on almost all devices. Luckily that includes the Pixel 2 and 2 XL.