The directory source/util/regress contains a program that runs through some of the basics of the uCR package to make sure things are working minimally. Several targets are supported already by this program. If you do a port, or find a problem in an existing port, it is a good idea to make sure this test program compiles and runs on your target.
This program should accumulate tests as bugs are found and corrected. Not every bug can be tested automatically, but if it can, please add the code to do so into the regress program. It may even be a good idea to include in any new features, classes or functions of uCR a feature_self_test() function, like the thread_self_test() and heap_self_test() functions that perform careful checks of threads and heaps respectively.