sudo apt install libmysqlclient-dev
mkdir -p ~/projects/build-mysql-drivers
cd ~/projects/build-mysql-drivers
~/Qt/5.12.2/gcc_64/bin/qmake MYSQL_PREFIX=/usr/include/mysql ~/Qt/5.12.2/Src/qtbase/src/plugins/sqldrivers
make sub-mysql
cp -v plugins/sqldrivers/libqsqlmysql.so ~/Qt/5.12.2/gcc_64/plugins/sqldrivers/