Careful debugging of the memory leak problem. At this stage,

stack frames for interpreted (but not primitive) functions appear not to be being
reclaimed, and the oblist doesn't seem to be being fully reclaimed.

src/io/print.c

@@ -116,6 +116,9 @@ void print_vso( URL_FILE *output, struct cons_pointer pointer ) {
         case HASHTV:
             print_map( output, pointer );
             break;
+        case STACKFRAMETV:
+            dump_stack_trace( output, pointer);
+            break;
             // \todo: others.
         default:
             fwprintf( stderr, L"Unrecognised vector-space type '%d'\n",