So unlike OSX FXRI on Debian (Etch) is a snap. This assumes you are running a self compiled 1.8.6 install with gems. All I had to do was apt-get install the following packages:
All you really need is the *-dev of course. Which resulted in the following additional packages being installed:
The following NEW packages will be installed:
libcupsys2-dev libexpat1-dev libfontconfig1-dev libfox-1.6-0 libfox-1.6-dev
libfox-1.6-doc libfreetype6-dev libgcrypt11-dev libgnutls-dev
libgpg-error-dev libjpeg62-dev liblzo-dev libopencdk8-dev libpng12-dev
libpopt-dev libtasn1-3-dev libtiff4-dev libtiffxx0c2 libxcursor-dev
libxfixes-dev libxft-dev libxrender-dev x11proto-fixes-dev
root@franz-t61:~/Desktop/Downloads/ruby-1.8.6# gem install fxri
Need to update 3 gems from http://gems.rubyforge.org
Install required dependency fxruby? [Yn] Y
Select which gem to install for your platform (i686-linux)
1. fxruby 1.6.11 (ruby)
2. fxruby 1.6.11 (mswin32)
3. fxruby 1.6.10 (mswin32)
4. fxruby 1.6.10 (ruby)
5. Skip this gem
6. Cancel installation
Building native extensions. This could take a while...
Successfully installed fxri-0.3.6
Successfully installed fxruby-1.6.11
Installing ri documentation for fxruby-1.6.11...
Installing RDoc documentation for fxruby-1.6.11...
And even more amazingly, all the fifteen thousand of the API docs (builtins and gems) are there! Now the only thing weird was I had to fix the path env in the fxri start script.