Comment by Retr0id

Try https://github.com/alex193a/Root-My-Pixel, worked on my 9a as of a few days ago (the version table in the readme is stale). I haven't checked the September update yet though (installing it now, to check).

Edit: September update for 8a has a kernel build from July. I believe it's still vulnerable but the exploit will need its offsets adjusting etc.