title: Errno::ENOENT: No such file or directory @ rb_sysopen - /tmp/
body: <p>I'm trying to push my app to Heroku, however I'm getting this rather arbitrary error:</p>
  
  <pre><code>Errno::ENOENT: No such file or directory @ rb_sysopen -\
         /tmp/build_.../config/aws.yml
         /tmp/build_.../vendor/bundle/ruby/2.1.0/gems/safe_yaml-1.0.3/lib/safe_yaml.rb:39:in `initialize'
         /tmp/build_.../vendor/bundle/ruby/2.1.0/gems/safe_yaml-1.0.3/lib/safe_yaml.rb:39:in `open'
         /tmp/build_.../vendor/bundle/ruby/2.1.0/gems/safe_yaml-1.0.3/lib/safe_yaml.rb:39:in `unsafe_load_file'
         /tmp/build_.../vendor/bundle/ruby/2.1.0/gems/safe_yaml-1.0.3/lib/safe_yaml.rb:24:in `load_file_with_options'
         /tmp/build_.../config/initializers/aws.rb:1:in `&lt;top (required)&gt;'
         /tmp/build_.../vendor/bundle/ruby/2.1.0/gems/activesupport-4.0.5/lib/active_support/dependencies.rb:223:in `load'
         /tmp/build_.../vendor/bundle/ruby/2.1.0/gems/activesupport-4.0.5/lib/active_support/dependencies.rb:223:in `block in load'
         /tmp/build_.../vendor/bundle/ruby/2.1.0/gems/activesupport-4.0.5/lib/active_support/dependencies.rb:214:in `load_dependency'
         /tmp/build_.../vendor/bundle/ruby/2.1.0/gems/activesupport-4.0.5/lib/active_support/dependencies.rb:223:in `load'
         /tmp/build_.../vendor/
  </code></pre>
  
  <p>I have the proper keys in the <code>aws.yml</code> file so I'm not sure why I'm getting this error, also it works fine locally.  I've tried removing the <code>/tmp</code> folder and letting Heroku re-generate it which also didn't work. How can I fix it?</p>