Install qTox (ubuntu 18.04 LTS, Mint 19.2 LTS)

Install qTox (ubuntu 18.04 LTS, Mint 19.2 LTS)

$ sudo apt-get install git -y

$ git clone https://github.com/qTox/qTox

$ git clone https://github.com/toktok/c-toxcore.git toxcore

$ sudo apt-get install build-essential cmake libavcodec-dev libavdevice-dev libavfilter-dev libavutil-dev libexif-dev libgdk-pixbuf2.0-dev libglib2.0-dev libgtk2.0-dev libopenal-dev libqrencode-dev libqt5opengl5-dev libqt5svg5-dev libsqlcipher-dev libswresample-dev libswscale-dev libxss-dev qrencode qt5-default qttools5-dev-tools qttools5-dev libtool autotools-dev automake checkinstall check libopus-dev libvpx-dev libsodium-dev libqt5concurrent5 -y

and now you are ready to compile:

1. Compiling toxcore

$ cd toxcore
$ cmake .
$ make -j $(nproc)
$ sudo make install
$ echo '/usr/local/lib/' | sudo tee -a /etc/ld.so.conf.d/locallib.conf
$ sudo ldconfig

2. Compile qTox

$ cd ../qTox
$ cmake .
$ make -j $(nproc)
$ sudo make install

3. To Run qtox

$ qtox

Reference:
https://askubuntu.com/questions/1047330/how-to-compile-and-install-qtox-from-github-on-ubuntu-18-04/1047398#1047398