axolotl [1] filed a request to merge ruby-bcrypt-ruby [2] into ruby-
bcrypt [3]:

It looks like the developers made a name change, as bcrypt-ruby has
not been updated since 2014; they appear to be using bcrypt as the
name. New package reflects this change.

[1] https://aur.archlinux.org/account/axolotl
[2] https://aur.archlinux.org/pkgbase/ruby-bcrypt-ruby
[3] https://aur.archlinux.org/pkgbase/ruby-bcrypt