There really is no need to run make clean on newly extracted sources

--- Makefile.orig	2021-02-11 09:31:32.955339000 +0000
+++ Makefile	2021-02-11 09:31:55.051680000 +0000
@@ -51,13 +51,10 @@
 	;; esac;
 	@date
 	@echo ""
-	cd $(IMAKESRC) && $(MAKE) $(FLAGS) clean
 	$(MAKE) $(MFLAGS) Makefile.boot
 	$(MAKE_CMD) $(MFLAGS) VerifyOS
 	$(MAKE_CMD) $(MFLAGS) Makefiles
 	$(MAKE_CMD) $(MFLAGS) Makefiles.doc
-	$(MAKE_CMD) $(MFLAGS) clean
-	$(MAKE_CMD) $(MFLAGS) clean.doc
 	$(MAKE_CMD) $(MFLAGS) includes
 	$(MAKE_CMD) $(MFLAGS) includes.doc
 	$(MAKE_CMD) $(MFLAGS) depend