Sometime between 20131023 and 20131031, /etc/release was broken.
Nearly all values are recorded as "(undefined)". It now looks like
this for me (with the same build command line as before):
NetBSD 6.99.25/amd64
Copyright (c) 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005,
2006, 2007, 2008, 2009, 2010, 2011, 2012, 2013
The NetBSD Foundation, Inc. All rights reserved.
Copyright (c) 1982, 1986, 1989, 1991, 1993
The Regents of the University of California. All rights reserved.
Build settings:
Build date Thu Oct 31 17:35:29 UTC 2013
Built by [email protected]
BSDOBJDIR = (undefined)
BSDSRCDIR = (undefined)
BUILDID = (undefined)
DESTDIR = '/archive/build/amd64.clang.20131031'
DISTRIBVER = (undefined)
EXTERNAL_TOOLCHAIN = (undefined)
HAVE_GCC = (undefined)
HAVE_GDB = (undefined)
HAVE_LLVM = 'yes'
HAVE_PCC = (undefined)
INSTALLWORLDDIR = (undefined)
KERNARCHDIR = (undefined)
KERNCONFDIR = (undefined)
KERNOBJDIR = (undefined)
KERNSRCDIR = (undefined)
MACHINE = 'amd64'
MACHINE_ARCH = 'x86_64'
MAKE = '/archive/build/tools.clang/bin/nbmake'
MAKECONF = (undefined)
MAKEFLAGS = ' -d e -m /archive/foreign/src/share/mk -j 4 -J 15,16
.MAKE.LEVEL.ENV=MAKELEVEL HOST_OSTYPE=NetBSD-6.99.24-amd64 MKOBJDIRS=yes
NOPOSTINSTALL=1 USETOOLS=yes _SRC_TOP_=/archive/foreign/src
_SRC_TOP_OBJ_=/usr/obj/src.amd64 _THISDIR_=etc/'
MAKEOBJDIR = '/disk/3/archive/obj/src.amd64/etc'
MAKEOBJDIRPREFIX = (undefined)
MAKEVERBOSE = (undefined)
MKATF = (undefined)
MKBFD = (undefined)
MKBINUTILS = (undefined)
MKCATPAGES = (undefined)
MKCRYPTO = (undefined)
MKCRYPTO_RC5 = (undefined)
MKCVS = (undefined)
MKDEBUG = (undefined)
MKDEBUGLIB = (undefined)
MKDOC = (undefined)
MKDTRACE = (undefined)
MKDYNAMICROOT = (undefined)
MKGCC = (undefined)
MKGCCCMDS = (undefined)
MKGDB = (undefined)
MKHESIOD = (undefined)
MKHTML = (undefined)
MKIEEEFP = (undefined)
MKINET6 = (undefined)
MKINFO = (undefined)
MKIPFILTER = (undefined)
MKKERBEROS = (undefined)
MKKYUA = (undefined)
MKLDAP = (undefined)
MKLINKLIB = (undefined)
MKLINT = (undefined)
MKLLVM = 'yes'
MKMAN = (undefined)
MKMANZ = (undefined)
MKMDNS = (undefined)
MKNLS = (undefined)
MKNPF = (undefined)
MKOBJ = (undefined)
MKOBJDIRS = 'yes'
MKPAM = (undefined)
MKPCC = (undefined)
MKPF = (undefined)
MKPIC = (undefined)
MKPICINSTALL = (undefined)
MKPICLIB = (undefined)
MKPOSTFIX = (undefined)
MKPROFILE = (undefined)
MKSHARE = (undefined)
MKSKEY = (undefined)
MKSOFTFLOAT = (undefined)
MKSTATICLIB = (undefined)
MKUNPRIVED = (undefined)
MKUPDATE = (undefined)
MKX11 = 'yes'
MKYP = (undefined)
NBUILDJOBS = (undefined)
NETBSDSRCDIR = '/archive/foreign/src'
NOCLEANDIR = (undefined)
NODISTRIBDIRS = (undefined)
NOINCLUDES = (undefined)
OBJMACHINE = (undefined)
RELEASEDIR = '/usr/obj/src.amd64/releasedir'
RELEASEMACHINEDIR = (undefined)
TOOLCHAIN_MISSING = (undefined)
TOOLDIR = '/archive/build/tools.clang'
USE_HESIOD = (undefined)
USE_INET6 = (undefined)
USE_JEMALLOC = (undefined)
USE_KERBEROS = (undefined)
USE_LDAP = (undefined)
USE_PAM = (undefined)
USE_SKEY = (undefined)
USE_YP = (undefined)
USETOOLS = 'yes'
USR_OBJMACHINE = (undefined)
X11SRCDIR = (undefined)
X11FLAVOUR = (undefined)
Thomas