pipeline {
  agent any
  stages {
    stage('Foo') {
        environment {
          // Failure: Expected name=value pairs
          3D_GLASSES = 'no'
          
          // Failure: Expected name=value pairs
          123ABC = 'bad'

          // Failure: expecting token in range: '0'..'9', found 'X'
          456_XYZ = 'numeric literal?'

          // Failure: ((what - about) - hyphens) is a binary expression
          what-about-hyphens = 'binary expression?'

          // OK
          LEGAL_GROOVY_IDENTIFIER = 'yay'
        }
        steps {
          sh 'env'
        }
    }
  }
}