FailedConsole Output

Started by upstream project "relay-lnt-ctmark" build number 9052
originally caused by:
 Started by upstream project "clang-stage1-RA" build number 661
 originally caused by:
  Started by an SCM change
  Started by an SCM change
  Started by an SCM change
  Started by an SCM change
  Started by an SCM change
  Started by an SCM change
  Started by an SCM change
  Started by an SCM change
  Started by an SCM change
  Started by an SCM change
  Started by an SCM change
  Started by an SCM change
  Started by an SCM change
  Started by an SCM change
  Started by an SCM change
  Started by an SCM change
  Started by an SCM change
  Started by an SCM change
[BFA] Scanning build for known causes...
[BFA] No failure causes found
[BFA] Done. 0s
java.lang.IllegalArgumentException: Null value not allowed as an environment variable: LLVM_REV
	at hudson.EnvVars.put(EnvVars.java:378)
	at hudson.model.StringParameterValue.buildEnvironment(StringParameterValue.java:59)
	at hudson.model.ParametersAction.buildEnvironment(ParametersAction.java:145)
	at hudson.model.Run.getEnvironment(Run.java:2383)
	at org.jenkinsci.plugins.workflow.job.WorkflowRun.getEnvironment(WorkflowRun.java:468)
	at org.jenkinsci.plugins.workflow.cps.CpsScmFlowDefinition.create(CpsScmFlowDefinition.java:106)
	at org.jenkinsci.plugins.workflow.cps.CpsScmFlowDefinition.create(CpsScmFlowDefinition.java:67)
	at org.jenkinsci.plugins.workflow.job.WorkflowRun.run(WorkflowRun.java:293)
	at hudson.model.ResourceController.execute(ResourceController.java:97)
	at hudson.model.Executor.run(Executor.java:429)
Finished: FAILURE