While compiling some code for BSD compatibility, the error occurred after invoking usr/ucb/cc. The unbundled compiler SPARCworks Professional C product was installed in /opt.
/usr/ucb/cc is a script that checks for the file /usr/ccs/bin/ucbcc and, if found, invokes it with appropriate library flags for BSD-compatibility compilation.
/usr/ucb/cc is part of the package SUNWscpu. /usr/ccs/bin/ucbcc is supposed to be a symbolic link to /opt/SUNWspro/bin/acc, which is created during the installation of the unbundled C compiler, SPROcc.