diff --git a/MatrixElement/BlobMEBase.cc b/MatrixElement/BlobMEBase.cc
--- a/MatrixElement/BlobMEBase.cc
+++ b/MatrixElement/BlobMEBase.cc
@@ -1,102 +1,106 @@
 // -*- C++ -*-
 //
 // This is the implementation of the non-inlined, non-templated member
 // functions of the BlobMEBase class.
 //
 
 #include "BlobMEBase.h"
 #include "ThePEG/Interface/ClassDocumentation.h"
 #include "ThePEG/EventRecord/Particle.h"
 #include "ThePEG/Repository/UseRandom.h"
 #include "ThePEG/Repository/EventGenerator.h"
 #include "ThePEG/Utilities/DescribeClass.h"
 
 using namespace ThePEG;
 
 BlobMEBase::BlobMEBase() {}
 
 BlobMEBase::~BlobMEBase() {}
 
 
 #include "ThePEG/PDT/EnumParticles.h"
 #include "ThePEG/MatrixElement/BlobDiagram.h"
 
 string BlobMEBase::ColourConnection::write(size_t& sourceCount,
 					   bool sink) const {
   string res;
   if ( members.size() == 2 ) {
     // standard connection
     for ( auto it = members.begin(); it != members.end(); ++it )
       res += std::to_string(*it) + " ";
   } else if ( members.size() == 3 ) {
     // source or sink
     for ( auto it = members.begin(); it != members.end(); ++it ) {
       res += std::to_string(*it) + " " + (sink ? "-":"") + std::to_string(sourceCount);
       if ( std::next(it) != members.end() )
 	res += ", ";
     }
     sourceCount += 1;
   } else {
     // not handled
     throw Exception() << "BlobMEBase::ColourConnection::write: Invalid colour connection information."
 		      << Exception::runerror;
   }
   return res;
 }
 
 void BlobMEBase::getDiagrams() const {
   multimap<tcPDPair,tcPDVector> proc = processes();
   int id = 1;
   for ( auto it = proc.begin(); it != proc.end(); ++it, ++id ) {
     BlobDiagram diag(id,it->first.first,it->first.second);
     for ( auto pit = it->second.begin(); pit != it->second.end(); ++pit )
       diag.operator,(*pit);
     add(new_ptr(diag));
   }
 }
 
 Selector<MEBase::DiagramIndex>
+#ifndef NDEBUG
 BlobMEBase::diagrams(const DiagramVector & diags) const {
+#else
+BlobMEBase::diagrams(const DiagramVector & ) const {
+#endif
   assert(diags.size()==1);
   Selector<DiagramIndex> sel;
   sel.insert(1.0, 0);
   return sel;
 }
 
 Selector<const ColourLines *>
 BlobMEBase::colourGeometries(tcDiagPtr diag) const {
   auto connections = colourConnections();
   ostringstream clines;
   size_t sourceCount = diag->partons().size() + 1;
   for ( auto it = connections.begin(); it != connections.end(); ++it ) {
     bool sink = (it->members.size()==3 && 
 		 (-it->members[0] > diag->nIncoming() ||
 		  it->members[0] <= diag->nIncoming() ) );
     clines << it->write(sourceCount,sink);
     auto nit = it; ++nit;
     if ( nit != connections.end() )
       clines << ",";
   }
   theColourLines.reset(clines.str());
   Selector<const ColourLines *> sel;
   sel.insert(1.0,&theColourLines);
   return sel;
 }
 
 CrossSection BlobMEBase::dSigHatDR() const {
   if ( !lastXCombPtr()->willPassCuts() )
     return ZERO;
   return
     (sqr(hbarc)/(2.*lastSHat())) *
     jacobian() * me2();
 }
 
 AbstractNoPIOClassDescription<BlobMEBase> BlobMEBase::initBlobMEBase;
 
 void BlobMEBase::Init() {
 
   static ClassDocumentation<BlobMEBase> documentation
     ("BlobMEBase is the base class for matrix elements producing blobs.");
 
 }