Ruby - Digest::Digest is deprecated; Use Digest

Question

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.

Answer 1

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

• https://github.com/fog/fog/pull/2473
• https://github.com/alexreisner/geocoder/pull/580
• https://github.com/ruby/ruby/pull/446

It's likely your Rails app depends on a gem that is using that old syntax.

Answer 2

If you're using bundler, a good way to find out what is causing the problem is to grep through all the gems defined in your Gemfile:

# grep (ack or ag) the problem code
bundle show --paths | xargs grep -r Digest::Digest                             

# here was my output
~/.gem/ruby/2.1.0/gems/fog-1.15.0/lib/fog/cloudstack.rb:    @@digest  = OpenSSL::Digest::Digest.new('sha1')
~/.gem/ruby/2.1.0/gems/fog-1.15.0/lib/fog/core/hmac.rb:      @digest = OpenSSL::Digest::Digest.new('sha1')
~/.gem/ruby/2.1.0/gems/fog-1.15.0/lib/fog/core/hmac.rb:        @digest = OpenSSL::Digest::Digest.new('sha256')

# update appropriate gems (in my case fog)
gem install fog
bundle update fog

Also make sure you aren't locked on a gem version in your Gemfile.

# change
gem 'fog', '~> 1.15.0'
# to
gem 'fog', '~> 1.0'
# or omit the version if you are a cowboy/girl

Answer 3

Use OpenSSL::Digest instead of deprecated OpenSSL::Digest::Digest