Solaris 9 has a kernel race condition which causes the final output written to the slave side of a pty to be lost upon the final close() of the slave device. This causes the dejagnu-based tests to fail intermittently. A workaround exists, but requires some help from the scheduler, and the "make check" must be executed from a shell with elevated priority limits.
Run something like
priocntl -s -c FX -m 30 -p 30 -i pid nnnn
as root, where nnnn
is the pid of the shell whose priority
limit you wish to raise.