Doing gem update --system might lose all your gems on Debian/Ubuntu

Well, if you installed RubyGems on your Ubuntu/Debian system via the package manager and are tired of waiting for the .deb package to get updated you might try doing this:

$ gem update --system

This caused a funny thing for me, all the installed gems disappeared! Well it is not that bad if you have your gem list backed up. If you do not. Than it is bad and you have some finding out to do. So remember back up you installed gems with

$ gem list > gems-list.txt

UPDATE: One more thingi I forgot is this.