--- grep-2.5.4/config.sub.orig	Sat Jan 25 11:56:17 2020
+++ grep-2.5.4/config.sub	Sat Jan 25 11:56:28 2020
@@ -1204,6 +1204,7 @@
 	# Each alternative MUST END IN A *, to match a version number.
 	# -sysv* is not here because it comes later, after sysvr4.
 	-gnu* | -bsd* | -mach* | -minix* | -genix* | -ultrix* | -irix* \
+	      | -serenity* \
 	      | -*vms* | -sco* | -esix* | -isc* | -aix* | -sunos | -sunos[34]*\
 	      | -hpux* | -unos* | -osf* | -luna* | -dgux* | -solaris* | -sym* \
 	      | -amigaos* | -amigados* | -msdos* | -newsos* | -unicos* | -aof* \