http://forum.canardpc.com/threads/110954-PATCH-fix-parallel-build-issues


don't run the clean target when building all as we run into parallel races:
 - memtest kicks off building of a bunch of .o files
 - clean runs in parallel which runs `rm` and deletes some of the new .o
 - memtest goes to link and fails because objects are missing

--- a/Makefile
+++ b/Makefile
@@ -22,7 +22,7 @@
 
 SELF_TEST_OBJS = test.o self_test.o cpuid.o random.o
 
-all: clean memtest.bin memtest
+all: memtest.bin memtest
 
 run_self_test : self_test
 	./self_test && touch run_self_test