I\'m currently upgrading an old rails app to use Rails 3 and Ruby 1.9.2, and RMagick is the last gem I need to install. However there doesn\'t seem to be any 1.9.2 download
This did the trick for me using ruby 2.0:
$ gem install rmagick --platform=ruby -- --with-opt-lib=C:/RailsInstaller/ImageMagick-6.7.7-Q8/lib --with-opt-include=c
:/RailsInstaller/ImageMagick-6.7.7-Q8/include
make sure to specify your own version of ImageMagick and the file path you installed it in & include the lib folder on the command