Not really. The Source code compatibility package is compatible with BSD 4.2, not SunOS 4.1.x. The consensus is that the library is broken beyond usability. If you use libucb to pick up some functions you need, it is often best to specify it after all other libraries and after libc with:
-lc -L/usr/ucblib -R/usr/ucblib -lucb
or preferably:
-lc /usr/ucblib/libucb.a