MarsSeed [1] filed a deletion request for ros-noetic-eigenpy [2]: Broken, unused, EOL library from 2022. ROS1 Noetic is EOL too, and its libraries are no longer compatible with Arch Linux, only with Python 3.9 and the already EOL Ubuntu 20.04 and Qt 5.12. Only the ROS2 distribution's packages are maintained by upstream and on AUR, and only those are viable to build and run on Arch Linux. [1] https://aur.archlinux.org/account/MarsSeed/ [2] https://aur.archlinux.org/pkgbase/ros-noetic-eigenpy/