better error message for seg in wiring but not in topology

diff --git a/layout/data2safety b/layout/data2safety
index 67f306484edbb68a47f7f3a63bd96ee5aef5a2aa..f2ea3f48aeafca36a1cac5a7fe4edbf24a212bb2 100755 (executable)
--- a/layout/data2safety
+++ b/layout/data2safety
@@ -602,7 +602,8 @@ sub writeout () {
                o(", ") if $end;
                o("{");
                $otherend= $segr->{Ends}[$comb][!$end];
-               defined $otherend or die "$seg $comb $end ?";
+               defined $otherend or
+                   die "segment $seg combination $comb end $end undefined\n";
                ($node,$side) = @$otherend;
                $nodeotherside= $nodes{$node}[1-$side];
                if (defined $nodeotherside) {