How to build for Pixel 2 (walleye)?

I was able to do that and got the build script to run until it filled my root partition on my Ubuntu install, over 100 GBs!

Is it expected that it will take up that much disk space? If so, is there a way to force the build onto another disk (my /home is on a separate 750 GB HDD, while / is on a 120 GB SSD)?