How to

• Follow the Chromium OS developer guide
• enter the cros_sdk
• Get this repository

mkdir $HOME/trunk/src/private-overlays
cd $HOME/trunk/src/private-overlays
git clone https://github.com/owulveryck/overlay-macbook-touchbar.git overlay-macbook-touchbar

Then

export BOARD=macbook-touchbar
./setup_board --board=${BOARD}