FailedConsole Output

Started by upstream project "relay-lnt-ctmark" build number 9051
originally caused by:
 Started by upstream project "clang-stage1-RA" build number 660
 originally caused by:
  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