Index: src/SymTab/Mangler.cc
===================================================================
--- src/SymTab/Mangler.cc	(revision 0a86a3094427d9c3e2c86bb1a3758bf2d3bf3728)
+++ src/SymTab/Mangler.cc	(revision 064cb183b9208c8bfca799c4a606ff5dc1b1aa8d)
@@ -172,5 +172,5 @@
 			for ( std::list< Expression* >::const_iterator param = params.begin(); param != params.end(); ++param ) {
 				TypeExpr *paramType = dynamic_cast< TypeExpr* >( *param );
-				assert(paramType && "Aggregate parameters should be type expressions");
+				assertf(paramType, "Aggregate parameters should be type expressions: %s", toString(*param).c_str());
 				maybeAccept( paramType->get_type(), *this );
 			}