mnussbaum [1] filed a orphan request for ruby-htmlentities [2]:

The latest version of the upstream package was released in 2015 and the package is still not updated. I've asked the maintainer to update and not heard back.

[1] https://aur.archlinux.org/account/mnussbaum/ [2] https://aur.archlinux.org/pkgbase/ruby-htmlentities/