title: Passing an environment variable to a shell script from Fastlane
body: <p>I'm running <A HREF="https://fastlane.tools/">Fastlane</A> (a continuous build tool for iOS) in order to execute a custom shell script for decrypting a file.</p>
  
  <p>This is the command.</p>
  
  <pre><code>sh "./decrypt.sh ENV['ENCRYPTION_P12']"
  </code></pre>
  
  <p>I cannot figured out a way to pass the environment variable to that script. Obviously, if I hardcode the pwd into the script, it works correctly.</p>
  
  <pre><code>sh "./decrypt.sh mypwd"
  </code></pre>
  
  <p>Any suggestions?</p>