Environment variables are empty

[zszabo14]

I'm trying to get plugin related environment variables, but they are NULL. How can I refer on those variables in a Pipeline script (Groovy).

Example:

pipeline {
agent any
	stages {
		stage('Stage 11') {
			steps {
				echo 'Hello world!'
				git(
					url: 'XXXXXXXXXXXXXXXXXXXXXXXXXXXXX',
					credentialsId: 'YYYYYYYYYYYYY',
					branch: "WWWWWWWWWWW"
				)
				script{
					echo 'Current Build: ' + currentBuild.displayName
					echo "${env.GITHUB_PR_BODY}"
					echo "${env.GITHUB_PR_TARGET_BRANCH}"
					echo "${env.GITHUB_PR_SOURCE_BRANCH}"
					def changeLogSets = currentBuild.changeSets
					echo 'Change Set size: ' + changeLogSets.size()
					for (int i = 0; i < changeLogSets.size(); i++) {
						def entries = changeLogSets[i].items
						for (int j = 0; j < entries.length; j++) {
							def entry = entries[j]
							echo "${entry.commitId} by ${entry.author} on ${new Date(entry.timestamp)}: ${entry.msg}"
							echo "msg: " + entry.msg
							echo "pkg: " + entry.msg.substring(entry.msg.indexOf("{")+1, entry.msg.indexOf("}"))
							def files = new ArrayList(entry.affectedFiles)
							for (int k = 0; k < files.size(); k++) {
								def file = files[k]
								echo "  ${file.editType.name} ${file.path}"
							}
						}
					}
				}
			}
		}
	}
} 

[KostyaSha]

Variables should be available when build was triggered by this plugin. Try check with shell env command

[zszabo14]

Yes, it was triggered by this plugin using the git webhook.
I printed out all environment variables: echo sh(returnStdout: true, script: 'env')
None of those are present.