MarsSeed [1] filed a deletion request for gtkmm3-plplot [2]: I've realized that upstream's latest stable release (v3.0.0) requires gtkmm4, not gtkmm3. So this is a legacy library now. As nothing depends on it on AUR, and there are no comments, I recommend deletion. It is safe to do so. [1] https://aur.archlinux.org/account/MarsSeed/ [2] https://aur.archlinux.org/pkgbase/gtkmm3-plplot/