In case somebody comes across this post by searching.
I have contributed a lot to FPCUnit, and opted to go a different route because FPCUnit is rather basic and contains some serious design flaws. May I suggest developers also look at FPTest (a DUnit2 fork). DUnit2 has massive improvements over DUnit, and both have massive improvements over FPCUnit.
http://wiki.freepascal.org/FPTestGet the source code for FPTest:
git clone git://github.com/graemeg/fptest.git