I've been getting this warning whenever I run my tests or start rails server.
When I run grep from .rvm folder I see the following:
grep -R 'Digest::Digest' .
./rubies/ruby-2.1.0/lib/ruby/2.1.0/openssl/digest.rb: warn('Digest::Digest is deprecated; Use Digest')
- additional references to openssl and ruby 2.1.0
So it looks like it's a Ruby 2.1.0 bug. Are there any fixes? There are no patches available yet as far as I can tell.
Whilst my app uses Fog and a bunch of other gems that have issues relating to this message, I'm using patched versions that don't have the bug. So I reckon Ruby is at fault here.
Borrowing the reply from this thread
OpenSSL::Digest::Digest has been discouraged to use from very ancient era such as Ruby 1.8 and finally was deprecated recently.
If you search for the error message, you will see that a lot of gems, including fog, were still using the deprecated syntax.
I assume it will take a while before all the gems will be updated. If you came across the deprecation in one of the libs you use, I encourage you to report it to the maintainer.
Here's a few examples
It's likely your Rails app depends on a gem that is using that old syntax.