Send mail for failing downsteam jobs to source committer, via Jenkins email-ext plugin.

committers.groovy

/* 
 * Save in $JENKINS_HOME/email-templates/committers.groovy
 * Under post build task "Editable Email Notification"
 * Global Recipient List: "${SCRIPT, script="committers.groovy"}"
 * 
 * Works with git, see comments for svn usage.
 */ 

def upstreamBuild = null
def cause = build.causes.find {
    if(it instanceof hudson.model.Cause.UpstreamCause) {
        return true
    }
    return false
}

try {
    while(cause != null) {
        upstreamBuild = hudson.model.Hudson.instance.getItem(cause.upstreamProject).getBuildByNumber(cause.upstreamBuild)
        if(upstreamBuild == null) {
            break;
        }
        cause = upstreamBuild.causes.find {
            if(it instanceof hudson.model.Cause.UpstreamCause) {
                return true
            }
            return false
        }
    }
} catch(e) {
    // do nothing
}

committers = []

if(upstreamBuild != null && upstreamBuild.changeSet != null) {
    upstreamBuild.changeSet.each() { cs ->
        email = hudson.model.Hudson.instance.getUser(cs.authorEmail) // GitChangeSet from git-plugin
        //if(cs.user != null) { // If using svn
        if(email != null) {
            //committers.add(user.id) // If using svn
            committers.add(email)
        }
    }
}

committers.unique().join(',')