qubeck [1] filed a deletion request for sing-box-bin [2]: >The submitted PKGBUILDs must not build applications already in any of the official binary repositories under any circumstances. I think it's safe to remove this package, since `sing-box` is in the `extra` repository now. There're no extra features either.
[1] https://aur.archlinux.org/account/qubeck/ [2] https://aur.archlinux.org/pkgbase/sing-box-bin/
