MarsSeed [1] filed a deletion request for ros-melodic-ros-type- introspection [2]:
Orphan ROS (Robot Operating System) package. 'Melodic': released 2018, EOL 2023-06-27. (Current: 'Noetic', supported until 2025.) The project uses AUR as their repo, and disown the deprecated packages instead of deleting them. [1] https://aur.archlinux.org/account/MarsSeed/ [2] https://aur.archlinux.org/pkgbase/ros-melodic-ros-type-introspection/
