From an question on answers.ros.org I noticed that we've ended up with semi overlapping duplicate entries for eigen.

I've submitted a PR to propose removing the less complete key eigen3 which only has fedora and gentoo rules. Those same rules exist using the eigen rosdep key.

Thie PR is here: https://github.com/ros/rosdistro/pull/13200 please comment if this will effect you adversely. If you're using this rule you can simply change to use the eigen key as a dependency instead of eigen3.