title: Gemset error when updating to Ruby 2.4.2
body: <p>I'm updating from Ruby 2.0 to 2.4.2 using RVM, and receive the following error messages during an install using <code>$ rvm install ruby-2.4.2</code>:</p>
  
  <pre><code>Making gemset ruby-2.4.2 pristine - please wait
  
  'command gem pristine --extensions bigdecimal --version 1.3.0 gem-wrappers --version 1.3.2 io-console --version 0.4.6 json --version 2.0.4 openssl --version 2.0.5 psych --version 2.2.2' failed, you need to fix this gems manually.
  Error running '__rvm_with ruby-2.4.2 gemset_pristine',
  please read /Users/myname/.rvm/log/1507820191_ruby-2.4.2/gemset.pristine-ruby-2.4.2.log
  
  Making gemset ruby-2.4.2@global pristine - please wait
  
  'command gem pristine --extensions bigdecimal --version 1.3.0 io-console --version 0.4.6 json --version 2.0.4 openssl --version 2.0.5 psych --version 2.2.2' failed, you need to fix this gems manually.
  Error running '__rvm_with ruby-2.4.2@global gemset_pristine',
  please read /Users/myname/.rvm/log/1507820191_ruby-2.4.2/gemset.pristine-ruby-2.4.2@global.log
  </code></pre>
  
  <p>I'm… not quite sure what this means, or what I should do next. Any thoughts? I'm running macOS 10.12.6.</p>
  
  <p>[Edit]: <a href="https://gist.github.com/gwijthoff/8a3e485537787604ac8d1bd4991ea889" rel="nofollow noreferrer">Here's a copy</a> of the error log.</p>