Just re-built #Kodi #Leia after messing with #MySQL it now requires it to build, once again.
Did have to create a symlink though:
# ln -sf /usr/include/mysql/mysql/udf_registration_types.h
In the /usr/include/mysql directory.
Turned out the libmysqlclient-dev package from #Oracle puts it in a different place to the #Ubuntu version. Or, perhaps Ubuntu creates the very same symlink (;*