These are some loose instructions for building the CloakCoin QT GUI (v2.1.0) on Ubuntu 16.04. I have informally tested this process once myself when building the application from source. You're mileage may vary.
# install git if you don't already have it
sudo apt install git
# clone the CloakCoin repository from GitHub
git clone https://github.com/CloakProject/CloakCoin
cd CloakCoin
# install the dependencies
sudo apt install -y \
build-essential \
qt5-default \
qt5-qmake \
libleveldb-dev \
libboost1.58-dev \
libcurl4-openssl-dev \
openssl \
libssl-dev \
libdb++-dev \
libevent-dev \
libboost-dev \
libboost-system-dev \
libboost-filesystem-dev \
libboost-program-options-dev \
libboost-thread-dev \
libminiupnpc-dev
# build from source
qmake && make
# if all went well you cloakcoin-qt should now
# have been created in the root of the repository folder
# the first time you launch the wallet, it will have to sync
# with the network. This takes forever if you don't already have
# a lot of the blockchain downloaded. You can download it before hand
# like this:
mkdir ~/.CloakCoin && cd ~/.CloakCoin
# download ~1.1 GB of blockchain data
wget https://backend.cloakcoin.com/wallet/v2/cloak_ldb.zip
unzip cloak_ldb.zip
rm cloak_ldb.zip
# now you are ready to launch the wallet
./cloakcoin-qt
# you can optionally copy cloakcoin-qt to a directory in your $PATH
# so that you can open it from anywhere like
sudo cp ./cloakcoin-qt /usr/local/bin
That's it! Again, these instructions have undergone limited testing, but they should be enough to get you started. Outdated linux instructions are on the wiki here.