MarsSeed [1] filed a deletion request for growl-for-linux [2]: Orphaned package, last updated in 2016.
Project discontinued in 2016; even the "Growl Network Protocol" documentation is offline. So I'd say it's safe to delete this. Nothing depends on it except its defunct Python binding package (pending deletion). [1] https://aur.archlinux.org/account/MarsSeed/ [2] https://aur.archlinux.org/pkgbase/growl-for-linux/
