amd64 base/head r284673 fails to build on amd64 base/head r284639, pilot error?

Hi,

Am I the only one who fails to build recent base/head (r284673) on 
pretty recent base/head (r284639)? This is on amd64 with ZFS and BEs.

Under the above circumstances, I got:

--- rescue.all__D ---
rescue
sh: rescue: not found
*** [rescue] Error code 127

make[5]: stopped in /usr/obj/usr/src/rescue/rescue
1 error

Yes, a ran a four-way build, -j 4. Maybe I should switch to single job 
builds.

Also, I see at lot of:

--- gnu/lib/libssp/libssp_nonshared__PL ---
ERROR: ctfconvert: rc = -1 No entry found [dwarf_next_cu_header_c(61)]

The one above happened very early in "stage 4.2: building libraries".

Complete build log (23 MiB) is available at 
http://ximalas.info/~trond/base-head-201506/make-buildworld-buildkernel-20150621-r284673.txt.

Using a one month old base/head (r284273) appears to get the job done, 
and I'm using that BE to build r284675 ATM, using serial jobs.

I haven't ruled out any pilot error on my behalf, or maybe my working 
copy of base/head is on the fritz.

My /etc/make.conf looks like this:

KERNCONF=VBOX

# DTrace for both base and ports. See https://wiki.freebsd.org/DTrace/KernelSupport.
STRIP=
CFLAGS+=-fno-omit-frame-pointer
WITH_CTF=1

WITH_PKGNG=yes
WITH_BDB6_PERMITTED=yes
WITH_SSP_PORTS=yes
WRKDIRPREFIX=/usr/ports/workdirs

TEX_DEFAULT=texlive

DEFAULT_VERSIONS=apache=2.4 bdb=5 firebird=2.5 gcc=4.8 lua=5.2 mysql=5.6 perl5=5.20 pgsql=9.4 php=5.6 python=2.7 python2=2.7 python3=3.4 ruby=2.2 tcltk=8.6

My /etc/src.conf looks like this:

CC=clang
CXX=clang++
CPP=clang-cpp

NO_WERROR=
WERROR=

WITH_CLANG_EXTRAS=yes
WITH_CLANG_FULL=yes
WITH_CTF=yes
WITH_GCC=yes
WITH_GNUCXX=yes
WITH_LIBCPLUSPLUS=yes
WITH_LLDB=yes
WITH_NAND=yes

My /etc/src-env.conf exists, but empty.

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