gentoo-overlay/net-misc/sipp/files/sipp-3.6.0-parallel-build.patch

--- sipp-3.6.0/Makefile.am.o	2019-12-22 10:40:37.766229344 +0200
+++ sipp-3.6.0/Makefile.am	2019-12-22 10:42:09.006266083 +0200
@@ -172,7 +172,7 @@
 
 # Ensure that after a reconfigure the source is cleaned.
 .autoclean: Makefile
-	make clean
+	$(MAKE) clean
 	echo > .autoclean
 BUILT_SOURCES = .autoclean