Just realized that as of 09/17/09 and revision 816090 of Solr you can now run specific unit tests instead of everything at once. This makes a developers life (mine) much easier because you no longer need to wait for all Solr’s tests to run just to test your particular piece of code.
To run specific testcase:
ant -Dtestcase=<CLASS NAME> junit
To run all tests for a specific package:
ant -Dtestpackage=<PACKAGE NAME> junit
To run all root tests of a specific package:
ant -Dtestpackageroot=<PACKAGE ROOT> junit