--- tests/unit/Makefile.orig.1	2020-08-04 09:52:39.060371000 -0600
+++ tests/unit/Makefile	2020-08-04 09:52:47.099995000 -0600
@@ -71,7 +71,7 @@
 ALL_KRML_FILES := $(filter-out krml/prims.krml,$(ALL_KRML_FILES))
 
 extract: $(ALL_KRML_FILES) # from .depend
-	-@mkdir out
+	-@mkdir -p out
 	$(KRML) -skip-compilation $^
 
 test.exe: $(ALL_KRML_FILES) krml/Test.krml