XCOMM is a comment line that should be processed by the pre-processor. The system uses Imake to generate makefiles; the Imake system uses cpp to concatenate an Imakefile with a rules file to produce a Makefile. The error you are seeing is common when this process doesn`t work, especially if your cpp is not ANSI-C (ISO-C). You don`t say what system you are on; read the README file carefully to determine what is expected in terms of compiler releases.