Index: src/ResolvExpr/AlternativeFinder.cc
===================================================================
--- src/ResolvExpr/AlternativeFinder.cc	(revision 0a22cda24fcefc09a8507da53bed0e32e13f4714)
+++ src/ResolvExpr/AlternativeFinder.cc	(revision be151bfb7d6e050ea312f07f97188a5d5debbbef)
@@ -605,5 +605,5 @@
 				Alternative newerAlt( newAlt );
 				newerAlt.env = newEnv;
-				assert( (*candidate)->get_uniqueId() );
+				assertf( (*candidate)->get_uniqueId(), "Assertion candidate does not have a unique ID: %s", toString( *candidate ).c_str() );
 				DeclarationWithType *candDecl = static_cast< DeclarationWithType* >( Declaration::declFromId( (*candidate)->get_uniqueId() ) );