I have the same issue. It looks like it's unable to find the libmysqlclient library. A temporary fix that has worked for me is the following:
export DYLD_LIBRARY_PATH=/usr/local/mysql/lib/ I am not sure where the config is specifying the load path or what it's set to but my mysql install did not appear to be in it. I'll post again if I find a more permanent solution.
Edit: Actually thisthis fix appears to more accurately address the problem.