After I build the makefile for an X application with xmkmf and run "make depend" and "make all", I get an error about how make doesn't know how to build config/util/rman. I got rid of it by changing #define BuildHtmlManPages YES to #define BuildHtmlManPages NO in /usr/lib/X11/config/Imake.tmpl, but obviously I shouldn't have had to do that. Either rman needs to be installed and the Imake templates need to know where to find it, or it needs to be disabled by default.
This has been fixed in 0.12