Upstream patch:
 * http://bugzilla-geant4.kek.jp/show_bug.cgi?id=1501
--- examples/advanced/xray_fluorescence/src/XrayFluoAnalysisManager.cc.orig
+++ examples/advanced/xray_fluorescence/src/XrayFluoAnalysisManager.cc
@@ -41,6 +41,7 @@
 // -------------------------------------------------------------------
 #ifdef G4ANALYSIS_USE
 
+#include "G4SystemOfUnits.hh"
 #include "G4VProcess.hh"
 #include <fstream>
 #include "G4ios.hh"
--- examples/advanced/xray_fluorescence/src/XrayFluoRunAction.cc
+++ examples/advanced/xray_fluorescence/src/XrayFluoRunAction.cc
@@ -35,6 +35,7 @@
 //
 // -------------------------------------------------------------------
 
+#include "G4SystemOfUnits.hh"
 #include "XrayFluoRunAction.hh"
 #include "G4Run.hh"
 #include "G4UImanager.hh"