Dropped in 3.0.2-r1.
libunique:3 is a different slot that only dead guimup and nautilus-actions use. Though it doesn't hurt to keyword it, it's no use and it rather triggers me to see about last rites.
libunique:1 is even more dead and deprecated than libunique:3, but because alive projects had migrated from :1 to :3 and then gtk3 GtkApplication uniqueness, and dead projects are stuck on libunique:1 and gtk2, it has more consumers :(
Understood, expected nothing else from you! ~arm64 added, closing.