bind missing module atom in retract/1 (#2182)

diff --git a/src/lib/builtins.pl b/src/lib/builtins.pl
index 2e18d94f44f231446511073bcfc6858b9517177f..9cb533d1f2d8e87da43709483d83007260252b1c 100644 (file)
--- a/src/lib/builtins.pl
+++ b/src/lib/builtins.pl
@@ -1214,6 +1214,9 @@ retract(Clause0) :-
        Body = true,
        retract_module_clause(Head, Body, Module)
     ;  Clause = (Head :- Body) ->
+       (  var(Module) -> Module = user
+       ;  true
+       ),
        retract_module_clause(Head, Body, Module)
     ).