Defining a variable in shell script portion of Jenkins Pipeline

Question

I'm trying to dynamically define a variable I use later in a some shell commands of my Jenkins pipeline and it's throwing an exception. I even tried to predefine the variable from an environment section to no avail. Is this a prohibited operation? My other variable myVar seems to work fine, but it's a constant through the pipeline.

pipeline {
    agent any

   environment {
     py2Ana=""
     myVar="ABCDE"
   }
    stages {
        stage('Stage1') {
            steps {
                sh """
                    echo myVar=$myVar
                    echo Find Anaconda2 Python installation...
                    py2Ana=`which -a python | grep --max-count=1 anaconda2`
                    if [[ -z "$py2Ana" ]]; then
                        echo ERROR: must have a valid Anaconda 2 distribution installed and on the PATH for this job.
                        exit 1 # terminate and indicate error
                    fi
                """
            }
        }
    }

Exception

groovy.lang.MissingPropertyException: No such property: py2Ana for class: groovy.lang.Binding
    at groovy.lang.Binding.getVariable(Binding.java:63)
    at org.jenkinsci.plugins.scriptsecurity.sandbox.groovy.SandboxInterceptor.onGetProperty(SandboxInterceptor.java:242)
    at org.kohsuke.groovy.sandbox.impl.Checker$6.call(Checker.java:288)
    at org.kohsuke.groovy.sandbox.impl.Checker.checkedGetProperty(Checker.java:292)
    at org.kohsuke.groovy.sandbox.impl.Checker.checkedGetProperty(Checker.java:268)
    at org.kohsuke.groovy.sandbox.impl.Checker.checkedGetProperty(Checker.java:268)
    at com.cloudbees.groovy.cps.sandbox.SandboxInvoker.getProperty(SandboxInvoker.java:29)
    at com.cloudbees.groovy.cps.impl.PropertyAccessBlock.rawGet(PropertyAccessBlock.java:20)
    at WorkflowScript.run(WorkflowScript:21)

Answer 1

As @jxramos stated, Jenkins is trying to resolve the variables in the script. It interprets any $string as a variable that needs substitution. The solution is to escape the $ of the in-script variables, as follows:

pipeline { 
  agent any 
  stages {
    stage('test stage'){
      steps {
        sh """#!/bin/bash
            myvar=somevalue
            echo "The value is \$myvar"
        """
      }
    }
  }
}