Domas and folks mydumper tool is awesome http://www.mydumper.org/ and I have been using it alot for MariaDB 5.2.x series. But it doesn't work with MySQL 5.5 official rpms as they strip out my_net_read from the RPM builds for MySQL 5.5
See original mydumper bug at https://bugs.launchpad.net/mydumper/+bug/803982
and the RHEL bug https://bugzilla.redhat.com/show_bug.cgi?id=728634
Now Remi repository managed to fix this by exporting my_net_read back into their Remi MySQL 5.5 builds see thread at http://forums.famillecollet.com/viewtopic.php?id=1699
Answer Answered by Vladislav Vaintroub in this comment.
Well, the reason why my_net_read is not exported is that it is nowhere documented, as such it does not have to be exported by the shared library. If there is a wish to use undocumented internal function, static client library works best for it (something mydumper folks should do in their CMakeLists.txt, in my opinion)