title: Why does the sqlite 1.2.3 gem install correctly for MRI but not for JRuby?
body: <p>If I call:</p>
  
  <pre><code>gem install sqlite3-ruby --v 1.2.3
  </code></pre>
  
  <p>it works for MRI</p>
  
  <p>but if I call:</p>
  
  <pre><code>jruby -S gem install sqlite3-ruby --v 1.2.3
  </code></pre>
  
  <p>it says it's trying to build a native extension (for Windows) and fails.</p>
  
  <p>Why are JRuby and MRI different in the way they treat gems?</p>