When I automatically the rdoc documentation of a gem I made, I always get this error/warning. I know there is a rdoc command-line option for defining the main page when invoking rdoc from the command line. But how do I pass this option from via a gemspec?
Also, Pickaxe 2 mentions a rdoc directive :main: that should set the main page. But this directive is unknown in the 1.8.2 (cygwin) distribution. Does the book refer to an upcoming version?