The unit tests for log4cxx were written for CPPUNIT (http://cppunit.sourceforge.net), an LGPL licensed unit testing framework. Dependence on LGPL'd libraries is problematic at best, see http://people.apache.org/~cliffs/3party.html. I'm going to bounce this off of legal-discuss, but wanted to go ahead an log the issue.
Migrating to a unit testing framework with a compatible license would likely be required before an official release. I'd suggest replacing the CPPUNIT_ macros with LOG4CXX_TEST_ macros and try to localize the necessary code to switch between frameworks to a few macros.
Options to explore:
APR's testing framework: Apache Portable Runtime includes a C test framework that could be copied into our SVN eliminating the need for a separate dependency.
rwtest: Apache stdcxx uses rwtest for its unit testing, assume more C++ oriented.
Any other suggestions?