groovy script to update matrix-parent build

[Lode Leroy]

Hi,

does anyone know whether it's possible and how to run a "system groovy script"
and make the first matrix sub-build set a parameter for all other sub-builds to read?

I was trying something like below, but I wonder if there is a better way, that works more reliably

thanks.

String changelist = build.rootBuild.buildVariableResolver.resolve('changelist')
if (changelist == null) {
  changelist = rexec('p4 changes -m 1 -s submitted', null, true, p4env)
  changelist = changelist.replaceAll(/^Change (\d+) on .*$/,'$1')
  if (build.rootBuild.buildVariableResolver.resolve('changelist') == null) {
     println "setting parent changelist to $changelist!"
     build.rootBuild.addAction(new ParametersAction(new StringParameterValue('changelist', changelist)));
  } else changelist = build.rootBuild.buildVariableResolver.resolve('changelist')
}