Gentoo's Bugzilla –
Attachment 382722 Details for
Bug 519692dev-db/mysql-workbench-6.1.7 with dev-db/mysql 5.5/5.6 - ld: warning: libmysqlclient_r.so.16, needed by /usr/lib/gcc/x86_64-pc-linux-gnu/4.8.3/../../../../lib64/libmysqlcppconn.so, not found (try using -rpath or -rpath-link)