def SLACK_CHANNEL = 'bar'

job('example') {
  publishers {
    slackNotifier {
      room("foo-${SLACK_CHANNEL}")
      notifyAborted(true)
      notifyFailure(true)
      notifyNotBuilt(false)
      notifyUnstable(true)
      notifyBackToNormal(true)
      notifySuccess(false)
      notifyRepeatedFailure(false)
      startNotification(false)
      includeTestSummary(false)
      includeCustomMessage(false)
      customMessage(null)
      buildServerUrl(null)
      sendAs(null)
      commitInfoChoice('NONE')
      teamDomain(null)
      authToken(null)
    }
  }
}

Processing provided DSL script
ERROR: (script, line 6) No signature of method: javaposse.jobdsl.plugin.structs.DescribableContext.room() is applicable for argument types: (org.codehaus.groovy.runtime.GStringImpl) values: [foo-bar]
Possible solutions: wait(), dump(), any(), find(), grep(), wait(long)
Finished: FAILURE