Random build failures (rump)

[coypu%SDF.ORG@localhost]

Hi,

There are sometimes build failures that seem to be from race conditions,
I've seen rump do it, maybe others too.

e.g. 
http://releng.netbsd.org/builds/netbsd-6/201610160430Z/ews4800mips.build.failed
http://releng.netbsd.org/builds/netbsd-6-1/201610122020Z/evbmips-mips64el.build.failed

It seems:

{src/sys/rump} % grep '\-l' */Makefile*
dev/Makefile.rumpdevcomp:RUMPDEVLDADD+=-lrumpdev_${var}
fs/Makefile.rumpfscomp:RUMPFSLDADD+=-lrumpfs_${var}
fs/Makefile.rumpfscomp:RUMPFSLDADD+=-lrumpvfs_${var}fs
fs/Makefile.rumpfscomp:RUMPFSLDADD+=-lrumpvfs_${var}
kern/Makefile.rumpkerncomp:RUMPKERNLDADD+=-lrumpkern_${var}
net/Makefile.rumpnetcomp:RUMPNETLDADD+=-lrumpnet_${var}

% ls librump
... rumpdev        rumpkern       rumpnet        rumpvfs

{src/sys/rump} % cat Makefile
#	$NetBSD: Makefile,v 1.7 2014/11/09 17:39:37 pooka Exp $
#

SUBDIR= 	include
SUBDIR+=	librump
SUBDIR+=	dev fs kern net
SUBDIR+=	share


Would adding
SUBDIR+=	.WAIT dev fs kern net

be the right thing to resolve this dependency?

thanks.