MarsSeed [1] filed a deletion request for libxfcegui4 [2]: Obsolete, EOL gtk2 based library from 2012.
No longer used by any working package. Also not compatible with the newer, gtk3-based xfce4 (since 2019). [1] https://aur.archlinux.org/account/MarsSeed/ [2] https://aur.archlinux.org/pkgbase/libxfcegui4/
