Index: layer_grp.h
===================================================================
--- layer_grp.h	(revision 32258)
+++ layer_grp.h	(revision 32259)
@@ -300,4 +300,9 @@
 /* Return true if the board has an outline layer with at least one object on it */
 rnd_bool pcb_has_explicit_outline(pcb_board_t *pcb);
 
+/* Return the thickness attribute of a layer group, optionally considering
+   the namespace based override attribute, when present; returns NULL if
+   attribute is not found. */
+const char *pcb_layergrp_thickness_attr(pcb_layergrp_t *grp, const char *namespace);
+
 #endif