[LRUG] Rubygems/json 1.8 error with Pry 0.10.4 / Ruby 2.4

[gvim]

I can't run the latest Pry 0.10.4 with Ruby 2.4.0 as it barfs:

<$HOME>.rbenv/versions/2.4.0/lib/ruby/2.4.0/rubygems/dependency.rb:310:in `to_specs': 
Could not find 'json' (~> 1.8) - did find: [json-2.0.2] 
(Gem::MissingSpecVersionError)

As far as I'm aware json 1.8 isn't compatible with Ruby 2.4.0. Any 
ideas/workarounds?

gvim