MarsSeed [1] filed a request to merge orocos-kdl [2] into orocos-kdl- git [3]:
Only the '-git' package works; whereas the stable one fails to build. Upstream has stopped releasing versioned tags since almost 4 years ago (Sep 2021) [a], and continues to maintain only the master branch. [b] [a]: http://github.com/orocos/orocos_kinematics_dynamics/tags [b]: http://github.com/orocos/orocos_kinematics_dynamics [1] https://aur.archlinux.org/account/MarsSeed/ [2] https://aur.archlinux.org/pkgbase/orocos-kdl/ [3] https://aur.archlinux.org/pkgbase/orocos-kdl-git/