Error building Hugo site from readme instructions

[PardusEidolon]

Using a Ubuntu image on VirtualBox I followed the README instructions as follows -

sudo apt-get git

sudo apt install nodejs
sudo apt install npm

git clone --recurse-submodules --depth 1 https://github.com/C3ETH/c3eth.github.io.git
cd c3eth.github.io

git submodule update --recursive
git pull --recurse-submodules

sudo npm install -D --save autoprefixer
sudo npm install -D --save postcss-cli

All fine until
hugo server

returned this error

[PardusEidolon]

Oh my god! goood lord!