How to get culprits or committers inside a Jenkins workflow with one or more SCMs

This is now possible using the email-ext plugin.

def to = emailextrecipients([[$class: 'CulpritsRecipientProvider'],                             [$class: 'DevelopersRecipientProvider'],                             [$class: 'RequesterRecipientProvider']])if (to != null && !to.isEmpty()) {    mail to: to, subject: "JENKINS", body: "See ${env.BUILD_URL}"}

However, if you just want to send an email on failures, you may want to use Mailer (based on the email-ext pipeline examples):

step([$class: 'Mailer',      notifyEveryUnstableBuild: true,      recipients: emailextrecipients([[$class: 'CulpritsRecipientProvider'],                                      [$class: 'RequesterRecipientProvider']])])

Using groovy within a pipeline script:

@NonCPS  // Necessary to allow .each to work.def changelist() {    def changes = ""    currentBuild.changeSets.each { set ->        set.each { entry ->            changes += "${entry.commitId} by ${entry.author.fullName}\n"        }    }    changes}

similar to the answer from @szym, but without the @NonCPS required:

def authors = currentBuild.changeSets.collectMany { it.toList().collect { it.author } }.unique()