Btw, I don't have time to do this right now, but it might be a good idea to try the testsuites for ruby, perl and python (and possibly others). They tend to break very easily on thread-related problems (as I'm sure you remember ;-)).
During development, I used glib2.0 and ruby1.9.1 as secondary testsuite (under kfreebsd-amd64). And there is a improvement.
The kfreebsd-i386 have been tested mainly by glibc testsuite itself. Petr