/usr/include/sys/un.h
/usr/include/rpc/types.h
/usr/include/math.h
/usr/include/sys/un.h
such a file does not exist on Interactive. You may like to generate it, if you don't like a warning from depend. It isn't needed to compile the sources successfully.
You could use the following to produce it:
#ifndef X_NO_SYS_UN struct sockaddr_un { short sun_family; /* AF_UNIX */ char sun_path[108]; /* path name (gag) */ }; #endif
/usr/include/sys/un.h
/usr/include/rpc/types.h
/usr/include/math.h