I repeated @agates's path and got the same result:
I flashed the latest android 9 using the google site.
Installed ubports installer on ubuntu computer.
Downloaded the config walleye.yml for my google pixel 2 and ran the installer with it. Installation was successful. Then flashed halium-boot_walleye.img via fastboot.
The phone won't boot and hangs on the google logo.
The /sys/fs/pstore folder is empty.