the reference solutions are not included.. therefore they shouldn't be tested :)

tests/Makefile

-TESTS = examples threads p1 userprog p2 vm p3 filesys p4
+#TESTS = examples threads p1 userprog p2 vm p3 filesys p4
+TESTS = examples threads userprog vm filesys
 
 PATH := $(shell pwd)/../src/utils:$(PATH)
 
@@ -69,10 +70,10 @@ examples::
 	$(clean)
 
 # Tests for the reference solutions.
-p1 p2 p3 p4::
-	$(mk-sandbox)
-	$(apply-patch)
-	$(run-tests)
-	$(grade-tests)
-	$(test-clean)
-	$(clean)
+#p1 p2 p3 p4::
+#	$(mk-sandbox)
+#	$(apply-patch)
+#	$(run-tests)
+#	$(grade-tests)
+#	$(test-clean)
+#	$(clean)