You need chez scheme. It's
available on Ubuntu 18.04 as chezscheme but the development happens
against git version. You will also need akku.
On ubuntu, you can try the following to install the system dependencies:
sudo apt install build-essential git python chezscheme
Then install akku and don't forget to add it
to your $PATH.
Once you have scheme, I assume you have git, you can proceed with the following:
$ git clone git@github.com:amirouche/zk.git
$ cd zk
$ make dev