Index: mt.scm
==================================================================
--- mt.scm
+++ mt.scm
@@ -200,16 +200,23 @@
     (if tconf
 	tconf
 	(let ((test-dirs (tests:get-tests-search-path *configdat*)))
 	  (let loop ((hed (car test-dirs))
 		     (tal (cdr test-dirs)))
+	    ;; Setting MT_LINKTREE here is almost certainly unnecessary. 
 	    (let ((tconfig-file (conc hed "/" test-name "/testconfig")))
 	      (if (and (file-exists? tconfig-file)
 		       (file-read-access? tconfig-file))
-		  (let ((newtcfg (read-config tconfig-file #f #f))) ;; NOTE: Does NOT run [system ...]
-		    (hash-table-set! *testconfigs* test-name newtcfg)
-		    newtcfg)
+		  (let ((link-tree-path (configf:lookup *configdat* "setup" "linktree"))
+			(old-link-tree  (get-environment-variable "MT_LINKTREE")))
+		    (if link-tree-path (setenv "MT_LINKTREE" link-tree-path))
+		    (let ((newtcfg (read-config tconfig-file #f #f))) ;; NOTE: Does NOT run [system ...]
+		      (hash-table-set! *testconfigs* test-name newtcfg)
+		      (if old-link-tree 
+			  (setenv "MT_LINKTREE" old-link-tree)
+			  (unsetenv "MT_LINKTREE"))
+		      newtcfg))
 		  (if (null? tal)
 		      (begin
 			(debug:print 0 "ERROR: No readable testconfig found for " test-name)
 			#f)
 		      (loop (car tal)(cdr tal))))))))))

Index: runs.scm
==================================================================
--- runs.scm
+++ runs.scm
@@ -93,16 +93,20 @@
 			  (configf:get-section runconfig section)))
 	      (list "default" target))
     (vector target runname testpatt keys keyvals envdat mconfig runconfig serverdat transport db toppath run-id)))
 
 (define (set-megatest-env-vars run-id #!key (inkeys #f)(inrunname #f)(inkeyvals #f))
-  (let* ((target      (or (common:args-get-target)
-			  (get-environment-variable "MT_TARGET")))
-	 (keys    (if inkeys    inkeys    (cdb:remote-run db:get-keys #f)))
-	 (keyvals (if inkeyvals inkeyvals (keys:target->keyval keys target)))
-	 (vals (hash-table-ref/default *env-vars-by-run-id* run-id #f)))
+  (let* ((target    (or (common:args-get-target)
+			(get-environment-variable "MT_TARGET")))
+	 (keys      (if inkeys    inkeys    (cdb:remote-run db:get-keys #f)))
+	 (keyvals   (if inkeyvals inkeyvals (keys:target->keyval keys target)))
+	 (vals      (hash-table-ref/default *env-vars-by-run-id* run-id #f))
+	 (link-tree (configf:lookup *configdat* "setup" "linktree")))
     ;; get the info from the db and put it in the cache
+    (if link-tree
+	(setenv "MT_LINKTREE" link-tree)
+	(debug:print 0 "ERROR: linktree not set, should be set in megatest.config in [setup] section."))
     (if (not vals)
 	(let ((ht (make-hash-table)))
 	  (hash-table-set! *env-vars-by-run-id* run-id ht)
 	  (set! vals ht)
 	  (for-each