title: AWS Deployment with Rails - configuration file in .ebextensions
body: <p>I have a configuration file in .ebextensions/packages.config.</p>
  
  <pre><code>packages: 
    yum:
      postgresql-devel: []
  </code></pre>
  
  <p>When I deploy on AWS ElacticBeanstalk, I have this error :</p>
  
  <blockquote>
    <p>[Instance: i-195762fc Module: AWSEBAutoScalingGroup ConfigSet: null] Command failed on instance. Return code: 1 Output: [CMD-AppDeploy/AppDeployStage0/EbExtensionPreBuild] command failed with error code 1: Error occurred during build: Yum does not have postgresql-devel available for installation.</p>
  </blockquote>
  
  <p>If you have an idea of the error I have made, I would be very grateful.</p>
  
  <p>Thank you.</p>