The unit test CodePatchSyncRequestVisitor fails from time to time. See http://jikesrvm.anu.edu.au/job/x86-pre-commit-main-repo/45/console for a recent report.
It seems that the test method codePatchingWorksWhenAThreadIsWaiting is not always terminating (even with a much more generous timeout than the test currently uses).
Edit: After deactivating the method, a similar problem occurs with the test for patching while sleeping. I've deactivated the tests for sleeping and parking in ae11b1fbb6b05b6b77bdf087896420fc9d9d62af. The test for suspend was deactivated in 0a6f1e4c121d43a7c53ec986d758b0643bb29839.