RichTel40CableMapping: Improve warning when source ID missing in tel40 links condition

Rich/RichFutureDAQ/src/lib/RichTel40CableMapping.cpp

@@ -37,6 +37,7 @@
 // STL
 #include <algorithm>
 #include <limits>
+#include <sstream>
 #include <string>
 #include <unordered_set>
 #include <utility>
@@ -173,7 +174,10 @@ void Tel40CableMapping::fillCableMaps( const LHCb::Detector::DeLHCb&
         if ( !linksActive.has_value() ) {
           // Only warn once per SourceID
           if ( warnSIDs.find( sourceID.data() ) == warnSIDs.end() ) {
-            warning( "Source ID '", sourceID.data(), "' is missing in LHCb Tel40 Link condition", endmsg );
+            std::ostringstream mess;
+            mess << "Source ID " << sourceID << " missing in LHCb Tel40 links condition. "
+                 << "Will fallback to RICH mapping condition for link status flags.";
+            warning( mess.str(), endmsg );
             warnSIDs.insert( sourceID.data() );
           }
         } else {