ext.machEnv = { topsrcdir ->
  // Allow to specify mozconfig in `local.properties` via
  // `mozilla-central.mozconfig=/path/to/mozconfig`.  This can't be an environment
  // variable because it's not feasible to specify environment variables under
  // Android Studio on some platforms including macOS.
  def localProperties = new Properties()
  def localPropertiesFile = new File(topsrcdir, 'local.properties')
  if (localPropertiesFile.canRead()) {
      localPropertiesFile.withInputStream {
          localProperties.load(it)
          logger.lifecycle("settings.gradle> Read local.properties: ${localPropertiesFile}")
      }
  }

  def localMozconfig = localProperties.getProperty("mozilla-central.mozconfig")

  def env = System.env.collect { k, v -> "${k}=${v}" }
  if (localMozconfig) {
      def envMozconfig = System.env.get('FOUND_MOZCONFIG')
      if (!envMozconfig || localMozconfig == envMozconfig) {
          logger.lifecycle("settings.gradle> Setting mozconfig from local.properties: ${localMozconfig}")
          env << "MOZCONFIG=${localMozconfig}"
      } else {
          logger.lifecycle("settings.gradle> Preferring mozconfig set in mach environment to mozconfig set in local.properties: ${envMozconfig}")
      }
  }

  return env
}