jenkins

AT_REVISION = ""
pipeline {
    agent {
        label 'agent2'
    }
    stages {
        stage('build_image_locally') {
            steps {
                script {
                    AT_REVISION="1234"
                }
                bat 'echo AT_REVISION = %AT_REVISION%'
                bat 'echo AT_REVISION = ${AT_REVISION}'
            }
        }
    }
}


Somehow the block below from an example seems to work. GIT_BRANCH is available after scope

stage ('Build') {
    when {
        expression {
            GIT_BRANCH = 'origin/' + sh(returnStdout: true, script: 'git rev-parse --abbrev-ref HEAD').trim()
            return GIT_BRANCH == 'origin/master' || params.FORCE_FULL_BUILD
        }
    }
    steps {
        parallel (
            linux: {
                build job: 'full-build-linux', parameters: [string(name: 'GIT_BRANCH_NAME', value: GIT_BRANCH)]
            },
            failFast: false)
    }
}