Index: head/Makefile.inc1
===================================================================
--- head/Makefile.inc1
+++ head/Makefile.inc1
@@ -2215,6 +2215,8 @@
 _basic_bootstrap_tools+=usr.sbin/services_mkdb usr.sbin/pwd_mkdb
 # sysctl/chflags are required for installkernel:
 _basic_bootstrap_tools+=sbin/sysctl bin/chflags
+# mkfifo is used by sys/conf/newvers.sh
+_basic_bootstrap_tools+=usr.bin/mkfifo
 
 .if ${MK_AMD} != "no"
 # unifdef is only used by usr.sbin/amd/libamu/Makefile
Index: head/sys/conf/newvers.sh
===================================================================
--- head/sys/conf/newvers.sh
+++ head/sys/conf/newvers.sh
@@ -86,7 +86,7 @@
 	local fifo
 
 	fifo=$(mktemp -u)
-	mkfifo -m 600 $fifo
+	mkfifo -m 600 $fifo || exit 1
 	$git_cmd --work-tree=${VCSTOP} diff-index HEAD > $fifo &
 	while read smode dmode ssha dsha status file; do
 		if ! expr $dsha : '^00*$' >/dev/null; then