mxcl/homebrew — pull request #16060 by niceview (2012-11-14 15:48:47+00:00)
Title: Ruby install without ri documentation (it is about 54M!!) Edit 

When we install ruby-1.9.3-p327, "make install" always install documentation for ri.
If you check "/usr/local/Cellar/ruby/1.9.3-p327/share/ri" folder, it is about 54Mbytes.
There is no difference between "brew install ruby" and "brew install ruby --with-doc".

If you don't need to install documentation (we usually use web instead of ri command), you have to use "--disable-install-doc" option for ./configure before make install.