Accessing the current Jenkins build in Groovy script

Question

I have created a Groovy script which is used in a System Groovy Script step in a Jenkins job which needs to access the current build of the current job.

T

Answer 1

This completes the answer from luka5z to exemplify how scriptler passes the listener to the groovy script:

import jenkins.model.*;
import hudson.model.*;
import hudson.util.*;
import hudson.tasks.*;
import hudson.plugins.git.*;
import hudson.scm.*
import jenkins.scm.*

def build = Thread.currentThread()?.executable
//def svn_branch = build.buildVariableResolver.resolve("SVN_BRANCH")

if (build instanceof AbstractBuild){
    def workspace = build.workspace
    //def job = build.parent
    def scm = build.parent.scm;
    //println "scm: $scm"

    if (scm instanceof hudson.scm.SubversionSCM) {
        scm.checkout(build, null/*Launcher*/, workspace /*workspace*/, listener/*listener*/, null /*changelogfile*/,null/*baseline*/)
    }else if (scm instanceof hudson.plugins.git.GitSCM) {
        scm.checkout(build, null/*Launcher*/, workspace /*workspace*/, listener/*listener*/, null /*changelogfile*/,null/*baseline*/)
    }
}

listener in Scriptler