Make sure our error message gives enough info about what it's doing

misc-scripts/datafiles/build_datafile_ftp_directory.pl

@@ -187,7 +187,7 @@ sub _process_datafile {
       
       $self->v("\tLinking %s -> %s", $filepath, $target);
       $self->v("\tRelative path is %s", $relative_path);
-      symlink($relative_path, $target) or die "Cannot symbolically link $filepath to $target: $!";
+      symlink($relative_path, $target) or die "Cannot symbolically link $filepath (${relative_path}) to $target: $!";
     }
   }
   return;