Notes for building Copperhead OS for the Pixel XL. This was done on Ubuntu 14.04.5 LTS, using GNU Make 3.81 (3.81-8.2ubuntu3) and Python 2.7.6 (2.7.6-8ubuntu0.2), as recommended on https://source.android.com/setup/requirements#software-requirements. All below instructions are specific to the Pixel XL (marlin) and come from https://copperhead.co/android/docs/building.
sudo apt-get update
sudo apt-get install git-core gnupg flex bison gperf build-essential zip curl zlib1g-dev gcc-multilib g++-multilib libc6-dev-i386 lib32ncurses5-dev x11proto-core-dev libx11-dev lib32z-dev ccache libgl1-mesa-dev libxml2-utils xsltproc unzip
sudo add-apt-repository ppa:git-core/ppa