I had a similar issue when using libcod with Ubuntu 18.04
Code:
Error while loading shared libraries: libmysqlclient.so.18: cannot open shared object file: No such file or directory
Probably because I compiled libcod on Ubuntu 14.04.
Fix is to uninstall current libraries;
Code:
sudo apt-get --purge remove libmysqlclient-dev:i386
Then download this .deb package and install;
Code:
wget http://launchpadlibrarian.net/247514894/libmysqlclient18_5.6.28-1ubuntu3_i386.deb
sudo apt install ./libmysqlclient18_5.6.28-1ubuntu3_i386.deb