I wanted the robot arm to be a bit autonomous from the computer, and I thought the bifferboard should be powerful enough to drive it. So I wanted to install ROS onto it. My bifferboard runs debian squeeze, and that means it’s not just a matter of installing the packages as with ubuntu. There is a dedicated wiki page about installing ROS on debian, so I was of the opinion that it can’t be that hard. Actually, I once tried to install ros electric already when the bifferboard was still running debian lenny, and I ran into an infinite loop. I was full of hope that this bug had been fixed now with the release of debian squeeze and ros fuerte. But in fact, the first infinite loop was even earlier this time. And after circumventing an issue in pip with the help of a pip dev, I ran into the one I experienced earlier. I was able to find a workaround this time and reported the issue to pyyaml. The bifferboard has no FPU, and from what I can observe in python no inf and strange handling of nan. (more…)