This script uses a patch from the rvm repo to patch a ruby-build package before installing it with rbenv. It uses ruby 1.9.3-p125 with gcdata patch, but it should work with any ruby / patch as long as they are compatible.

rbenv-patch

#!/bin/sh

mkdir /tmp/ruby-build-patch
cd /tmp/ruby-build-patch

# download and patch the ruby sources
wget http://ftp.ruby-lang.org/pub/ruby/1.9/ruby-1.9.3-p125.tar.gz
tar xzf ruby-1.9.3-p125.tar.gz
cd ruby-1.9.3-p125
curl https://raw.github.com/wayneeseguin/rvm/master/patches/ruby/1.9.3/p125/gcdata.patch | patch -p1
cd ..
mv ruby-1.9.3-p125 ruby-1.9.3-p125-gcdata
tar -cvf ruby-1.9.3-p125-gcdata.tar.gz ruby-1.9.3-p125-gcdata

# download and patch the ruby-build version definition
wget https://raw.github.com/sstephenson/ruby-build/master/share/ruby-build/1.9.3-p125
sed 's|"ruby-1.9.3-p180.*|"ruby-1.9.3-p180-gcdata" "file:///tmp/ruby-build-patch/ruby-1.9.3-p125-gcdata"|' < 1.9.3-p125 > 1.9.3-p125-gcdata

#install the patched version
rbenv install /tmp/1.9.3-p125-gcdata
cd /tmp
rm -rf ruby-build-patch

This version is working for Ruby 1.9.3p484 and the gcdata patch: https://gist.github.com/edelgado/208005f645b27c0eda90