Index: openacs-4/packages/xotcl-core/tcl/01-debug-procs.tcl
===================================================================
RCS file: /usr/local/cvsroot/openacs-4/packages/xotcl-core/tcl/01-debug-procs.tcl,v
diff -u -r1.89 -r1.90
--- openacs-4/packages/xotcl-core/tcl/01-debug-procs.tcl	25 Apr 2018 19:47:48 -0000	1.89
+++ openacs-4/packages/xotcl-core/tcl/01-debug-procs.tcl	9 May 2018 15:33:33 -0000	1.90
@@ -216,7 +216,7 @@
 
 namespace eval ::xo {
   proc slotobjects cl {
-    set so {}
+    set so [list]
     array set names ""
     foreach c [list $cl {*}[$cl info heritage]] {
       foreach s [$c info slots] {