Index: openacs-4/packages/acs-bootstrap-installer/tcl/00-proc-procs.tcl
===================================================================
RCS file: /usr/local/cvsroot/openacs-4/packages/acs-bootstrap-installer/tcl/00-proc-procs.tcl,v
diff -u -r1.22 -r1.23
--- openacs-4/packages/acs-bootstrap-installer/tcl/00-proc-procs.tcl	11 Mar 2005 23:41:52 -0000	1.22
+++ openacs-4/packages/acs-bootstrap-installer/tcl/00-proc-procs.tcl	11 Mar 2005 23:48:12 -0000	1.23
@@ -745,7 +745,7 @@
         set c [catch {::eval $procname $args} ret]
         switch -exact $c {
             0 { # code ok
-                if {[llength $ret] > 0} { 
+                if {[llength $ret] > 0} {
                     lappend returns $ret
                 }
             }
@@ -772,6 +772,11 @@
             }
         }
     }
+
+    if {![string equal impl *] && ![info exists c]} {
+        error "callback $callback implementation $impl does not exist"
+    }
+
     return $returns
 }