The relevant message in the log seems to be:
:info:build -compiler-check:
:info:build [echo] This version of MySQL Connector/J requires a compiler from Java-1.4 or Java-1.5 to be used, set your JAVA_HOME property to point to one of these versions of the JDK.
:info:build [echo]
:info:build [echo] Compiling this version also requires Java-6 for compiling the JDBC-4.0 implementation, please set the full path to the javac executable with the property "com.mysql.jdbc.java6.javac"
:info:build [echo] and the full path to the rt.jar from Java-6 with the property "com.mysql.jdbc.java6.rtjar".
:info:build [echo]
This port has no maintainer, so if you can make a patch to fix the problem, let us know.