Why do I get an "undefined symbol for h_errno error" when using the ODBC-ODBC Bridge?

Some versions of the Easysoft ODBC-ODBC Bridge client for Solaris aren't built against the Solaris threads library. As a result, if you attempt to link a threaded program with the libesoobclient shared object, you'll probably get an "undefined symbol for h_errno" error. When a program is built threaded, h_errnop is defined instead of h_errno.

An example where you might get this is if you build the unixODBC Driver Manager with threads (the default configuration) and then try to use the ODBC-ODBC Bridge with it. The solution is to rebuild the unixODBC Driver Manager without threads (include --enable-threads=no in the configure line).