title: gem install fails with "Could not find a valid gem 'yaml'"
body: <p>I'm building a gem from a <em>currently working</em> ruby program. It's using jruby 1.7.12 and, among other things, does a "require 'yaml". For the gem, my Gemfile contains:</p>
  
  <pre><code>source 'https://rubygems.org'
  gemspec
  </code></pre>
  
  <p>When I run</p>
  
  <pre><code>gem build program.gemspec 
  </code></pre>
  
  <p>that works just fine, but when I run</p>
  
  <pre><code>gem install program-0.15.01.gem
  </code></pre>
  
  <p>it fails with</p>
  
  <pre><code>ERROR:  Could not find a valid gem 'yaml' (&gt;= 0) in any repository 
  ERROR:  Possible alternatives: aml, cyaml, haml, maml, raml  
  </code></pre>
  
  <p>Doesn't make any sense since the yaml module is part of the ruby 1.9.3 standard library. </p>
  
  <p>I've upgraded to the latest rubygems (2.4.5).</p>
  
  <p>What the heck am I missing?</p>