--- a/make/common/FindTests.gmk	Fri Mar 03 12:57:57 2017 +0100
+++ b/make/common/FindTests.gmk	Mon Mar 06 13:39:34 2017 +0100
@@ -52,7 +52,8 @@
     $1_JTREG_GROUP_FILES := $$(addprefix $$($1_JTREG_TESTROOT)/, \
         $$($1_JTREG_GROUP_FILENAMES))
     $1_JTREG_TEST_GROUPS := $$(strip $$(shell $$(SED) -n \
-        -e 's/\([^ ]*\)\w*=.*/\1/gp' $$($1_JTREG_GROUP_FILES) | $$(SORT) -u))
+        -e 's/\([^ ]*\)\w*=.*/\1/gp' $$(wildcard $$($1_JTREG_GROUP_FILES)) \
+        | $$(SORT) -u))
   endif
 endef