From 412178a54ff7911d184f3e7c7bf38bb0361b4b4f Mon Sep 17 00:00:00 2001
From: will-cern <will@cern.ch>
Date: Thu, 14 Dec 2023 15:23:04 +0000
Subject: [PATCH] ensure globalObservables is always created, even if no
 lumiError

---
 roofit/histfactory/src/HistoToWorkspaceFactoryFast.cxx | 1 +
 1 file changed, 1 insertion(+)

diff --git a/roofit/histfactory/src/HistoToWorkspaceFactoryFast.cxx b/roofit/histfactory/src/HistoToWorkspaceFactoryFast.cxx
index c24a012919f96..e146d1aaf616f 100644
--- a/roofit/histfactory/src/HistoToWorkspaceFactoryFast.cxx
+++ b/roofit/histfactory/src/HistoToWorkspaceFactoryFast.cxx
@@ -832,6 +832,7 @@ RooArgList HistoToWorkspaceFactoryFast::createObservables(const TH1 *hist, RooWo
       constraintTermNames.push_back("lumiConstraint");
     } else {
       proto.var("Lumi")->setConstant();
+      proto.defineSet("globalObservables",RooArgSet()); // create empty set as is assumed it exists later
     }
     //proto.factory("SigXsecOverSM[1.,0.5,1..8]");
     ///////////////////////////////////