title: Jenkins Pipeline Step withEnv does not work without BASH
body: <p>I've trouble setting an environment variable for a container in an Jenkins pipeline.
  It seems, that "withEnv" does not work nicely with machines without bash.</p>
  
  <p>Can you confirm that? I cannot find an official statement ;-)</p>
  
  <p>When I run the following snippet on the Jenkins slave it works.
  But when it is executed in a docker container without BASH "$test" isn't set.</p>
  
  <pre><code> withEnv(["test='asd'"]){
        sh 'echo $test'
   }
  </code></pre>
  
  <p><a href="https://jenkins.io/doc/pipeline/steps/workflow-basic-steps/#code-withenv-code-set-environment-variables" rel="nofollow noreferrer">https://jenkins.io/doc/pipeline/steps/workflow-basic-steps/#code-withenv-code-set-environment-variables</a></p>