title: How to set PATH in Jenkins Declarative Pipeline
body: <p>In Jenkins scripted pipeline you can set PATH env variable like this :</p>
  
  <pre><code>node {
     git url: 'https://github.com/jglick/simple-maven-project-with-tests.git'
     withEnv(["PATH+MAVEN=${tool 'M3'}/bin"]) {
        sh 'mvn -B verify'
     }
  }
  </code></pre>
  
  <p>Notice the <em>PATH+MAVEN</em> as explained here <a href="https://jenkins.io/doc/pipeline/steps/workflow-basic-steps/#code-withenv-code-set-environment-variables" rel="noreferrer">https://jenkins.io/doc/pipeline/steps/workflow-basic-steps/#code-withenv-code-set-environment-variables</a> :</p>
  
  <blockquote>
    <p>A list of environment variables to set, each in the form
    VARIABLE=value or VARIABLE= to unset variables otherwise defined. You
    may also use the syntax PATH+WHATEVER=/something to prepend /something
    to $PATH.</p>
  </blockquote>
  
  <p>But I didn't find how to do it in declarative pipeline using environment syntax (as explained here : <a href="https://jenkins.io/doc/pipeline/tour/environment" rel="noreferrer">https://jenkins.io/doc/pipeline/tour/environment</a>).</p>
  
  <pre><code>environment {
      DISABLE_AUTH = 'true'
      DB_ENGINE    = 'sqlite'
  }
  </code></pre>
  
  <p>Ideally I would like to update the PATH to use custom tools for all my stages.</p>