title: How to fix "uninitialized constant Gem::GEM_PRELUDE_SUCKAGE" in RubyGems tasks
body: <p>My RubyGems isn't working, throwing an error which goes as follows, triggering (nearly) on any Gem task:</p>
  
  <pre><code>/System/Library/Frameworks/Ruby.framework/Versions/2.0/usr/lib/ruby/2.0.0/rubygems.rb:1081:in `&lt;top (required)&gt;': uninitialized constant Gem::GEM_PRELUDE_SUCKAGE (NameError)
      from &lt;internal:gem_prelude&gt;:1:in `require'
      from &lt;internal:gem_prelude&gt;:1:in `&lt;compiled&gt;'
  </code></pre>
  
  <p>I'm new to Ruby / RubyGems / installing Ruby and all I know is that an uninitialized constant is essentially a undefined variable. It could also be possible that it's something with Ruby itself, although the -><code>Gem:GEM</code>&lt;-<code>_PRELUDE_SUCKAGE</code> points me to RubyGems.</p>
  
  <p>In a nutshell, I installed a bunch of Ruby things (think RVM, rbenv, etc.) to develop Ruby on Rails, as I thought it would be a good way to learn Ruby.</p>
  
  <p>Well, after going through a long and tedious process to upgrade Ruby to 2.6.3, then downgrade to 2.5.5 and then 2.4.0, then back up to 2.5.5 and solving downgrade issues, RubyGems throws the error. I settled on 2.5.5 because 2.6.3 caused errors and 2.4.0 was too early of a version.</p>
  
  <p>It's causing all sorts of errors, like HAML not compiling and Rails not making a controller. I really don't know what's happening.</p>
  
  <p>If I run <code>gem install [gem name]</code>, it throws the error. Running <code>rails generate controller [name] index</code> (for those not familiar to Rails this creates, well, a controller) it throws the error. Doing anything really with the <code>gem</code> command causes the error, except for <code>gem server</code>. </p>
  
  <p>If I upgrade back up to the latest Ruby version, I fear that my <code>gem</code> command will go all wonky again and I'll have to go through another day of troubleshooting versions. How do I fix this, or at least get rid of the message so I can create things again?</p>