ino64? r318606 -> r318739 OK; r318739 -> r318781 fails SIGSEGV

Yesterday's in-place src update (r318606 -> r318739) was a bit more
"interesting" than usual; as has been noted elsewhere, it really is
necessary to boot the new kernel before the "make installworld"
completes successfully.  That said, it ("make installworld") did
complete successfully, and a followup reboot/smoke test worked without
incident.

For today's update, sources are now at r318781; both laptop and build
machine fail identically during ">>> stage 4.2: building libraries":

...
Building /common/S4/obj/usr/src/lib/libc/strsignal.pico
Building /common/S4/obj/usr/src/lib/libc/libc.a
--- libc.a ---
building static c library
Building /common/S4/obj/usr/src/lib/libc/libc.so.7
Building /common/S4/obj/usr/src/lib/libc/libc_pic.a
--- libc.so.7 ---
building shared library libc.so.7
--- libc_pic.a ---
building special pic c library
--- libc.so.7 ---
cc: error: unable to execute command: Segmentation fault (core dumped)
cc: error: linker command failed due to signal (use -v to see invocation)
*** [libc.so.7] Error code 254

bmake[4]: stopped in /usr/src/lib/libc
.ERROR_TARGET='libc.so.7'
.ERROR_META_FILE='/common/S4/obj/usr/src/lib/libc/libc.so.7.meta'
.MAKE.LEVEL='4'
MAKEFILE=''
.MAKE.MODE='meta missing-filemon=yes missing-meta=yes silent=yes verbose'
.CURDIR='/usr/src/lib/libc'
.MAKE='/usr/obj/usr/src/make.amd64/bmake'
.OBJDIR='/usr/obj/usr/src/lib/libc'
.TARGETS='all'
DESTDIR='/usr/obj/usr/src/tmp'
LD_LIBRARY_PATH=''
MACHINE='amd64'
MACHINE_ARCH='amd64'
MAKEOBJDIRPREFIX='/usr/obj'
MAKESYSPATH='/usr/src/share/mk'
MAKE_VERSION='20160604'
PATH='/usr/obj/usr/src/tmp/legacy/usr/sbin:/usr/obj/usr/src/tmp/legacy/usr/bin:/usr/obj/usr/src/tmp/legacy/bin:/usr/obj/usr/src/tmp/usr/sbin:/usr/obj/usr/src/tmp/usr/bin:/sbin:/bin:/usr/sbin:/usr/bin'
SRCTOP='/usr/src'
OBJTOP='/usr/obj/usr/src'
.MAKE.MAKEFILES='/usr/src/share/mk/sys.mk /usr/src/share/mk/local.sys.env.mk /usr/src/share/mk/src.sys.env.mk /etc/src-env.conf /usr/src/share/mk/bsd.mkopt.mk /usr/src/share/mk/bsd.suffixes.mk /etc/make.conf /usr/src/share/mk/local.sys.mk /usr/src/share/mk/src.sys.mk /etc/src.conf /usr/src/lib/libc/Makefile /usr/src/share/mk/src.opts.mk /usr/src/share/mk/bsd.own.mk /usr/src/share/mk/bsd.opts.mk /usr/src/share/mk/bsd.cpu.mk /usr/src/share/mk/bsd.compiler.mk /usr/src/share/mk/bsd.compiler.mk /usr/src/lib/libc/amd64/Makefile.inc /usr/src/lib/libc/db/Makefile.inc /usr/src/lib/libc/db/btree/Makefile.inc /usr/src/lib/libc/db/db/Makefile.inc /usr/src/lib/libc/db/hash/Makefile.inc /usr/src/lib/libc/db/man/Makefile.inc /usr/src/lib/libc/db/mpool/Makefile.inc /usr/src/lib/libc/db/recno/Makefile.inc /usr/src/lib/libc/compat-43/Makefile.inc /usr/src/lib/libc/gdtoa/Makefile.inc /usr/src/lib/libc/gen/Makefile.inc /usr/src/lib/libc/amd64/gen/Makefile.inc /usr/src/lib/libc/gmon/Makefile.inc /usr/src/lib/libc/iconv/Makefile.inc /usr/src/lib/libc_nonshared/Makefile.iconv /usr/src/lib/libc/inet/Makefile.inc /usr/src/lib/libc/isc/Makefile.inc /usr/src/lib/libc/locale/Makefile.inc /usr/src/lib/libc/md/Makefile.inc /usr/src/lib/libc/nameser/Makefile.inc /usr/src/lib/libc/net/Makefile.inc /usr/src/lib/libc/nls/Makefile.inc /usr/src/lib/libc/posix1e/Makefile.inc /usr/src/lib/libc/regex/Makefile.inc /usr/src/lib/libc/resolv/Makefile.inc /usr/src/lib/libc/stdio/Makefile.inc /usr/src/lib/libc/stdlib/Makefile.inc /usr/src/lib/libc/amd64/stdlib/Makefile.inc /usr/src/lib/libc/stdlib/jemalloc/Makefile.inc /usr/src/lib/libc/stdtime/Makefile.inc /usr/src/lib/libc/string/Makefile.inc /usr/src/lib/libc/amd64/string/Makefile.inc /usr/src/lib/libc/sys/Makefile.inc /usr/src/sys/sys/syscall.mk /usr/src/lib/libc/amd64/sys/Makefile.inc /usr/src/lib/libc/secure/Makefile.inc /usr/src/lib/libc/rpc/Makefile.inc /usr/src/lib/libc/uuid/Makefile.inc /usr/src/lib/libc/xdr/Makefile.inc /usr/src/lib/libc/x86/sys/Makefile.inc /usr/src/lib/libc/yp/Makefile.inc /usr/src/lib/libc/capability/Makefile.inc /usr/src/share/mk/bsd.lib.mk /usr/src/share/mk/bsd.init.mk /usr/src/share/mk/local.init.mk /usr/src/share/mk/src.init.mk /usr/src/lib/libc/../Makefile.inc /usr/src/share/mk/bsd.libnames.mk /usr/src/share/mk/src.libnames.mk /usr/src/share/mk/bsd.symver.mk /usr/src/share/mk/bsd.nls.mk /usr/src/share/mk/bsd.files.mk /usr/src/share/mk/bsd.incs.mk /usr/src/share/mk/bsd.confs.mk /usr/src/share/mk/bsd.links.mk /usr/src/share/mk/bsd.dep.mk /usr/src/share/mk/bsd.clang-analyze.mk /usr/src/share/mk/bsd.obj.mk /usr/src/share/mk/bsd.subdir.mk /usr/src/share/mk/bsd.sys.mk'
.PATH='. /usr/src/lib/libc /usr/src/lib/libc/db/btree /usr/src/lib/libc/db/db /usr/src/lib/libc/db/hash /usr/src/lib/libc/db/man /usr/src/lib/libc/db/mpool /usr/src/lib/libc/db/recno /usr/src/lib/libc/compat-43 /usr/src/lib/libc/gdtoa /usr/src/lib/libc/amd64/gen /usr/src/lib/libc/gen /usr/src/contrib/libc-pwcache /usr/src/contrib/libc-vis /usr/src/lib/libc/gmon /usr/src/lib/libc/iconv /usr/src/lib/libc/inet /usr/src/lib/libc/isc /usr/src/lib/libc/locale /usr/src/lib/libmd /usr/src/lib/libc/nameser /usr/src/lib/libc/net /usr/src/lib/libc/nls /usr/src/lib/libc/posix1e /usr/src/lib/libc/regex /usr/src/lib/libc/resolv /usr/src/lib/libc/stdio /usr/src/lib/libc/amd64/stdlib /usr/src/lib/libc/stdlib /usr/src/lib/libc/stdlib/jemalloc /usr/src/lib/libc/stdtime /usr/src/contrib/tzcode/stdtime /usr/src/lib/libc/amd64/string /usr/src/lib/libc/string /usr/src/sys/libkern /usr/src/lib/libc/amd64/sys /usr/src/lib/libc/sys /usr/src/lib/libc/secure /usr/src/lib/libc/rpc /usr/src/lib/libc/. /usr/src/lib/libc/uuid /usr/src/lib/libc/xdr /usr/src/lib/libc/x86/sys /usr/src/lib/libc/yp /usr/src/sys/kern /usr/src/lib/libc/capability'
1 error
....

I'm using 'WITH_META_MODE=yes' -- have been for nearly a year (of daily
updates) on both machines.

I tried "make clean", then re-tried the build; the resulting failure
looks "functionally identical" to me:

...
Building /common/S4/obj/usr/src/lib/libc/zh_CN.UTF-8.cat
Building /common/S4/obj/usr/src/lib/libc/libc.a
--- libc.a ---
building static c library
Building /common/S4/obj/usr/src/lib/libc/libc.so.7
Building /common/S4/obj/usr/src/lib/libc/libc_pic.a
--- libc.so.7 ---
building shared library libc.so.7
--- libc_pic.a ---
building special pic c library
--- libc.so.7 ---
cc: error: unable to execute command: Segmentation fault (core dumped)
cc: error: linker command failed due to signal (use -v to see invocation)
*** [libc.so.7] Error code 254

bmake[4]: stopped in /usr/src/lib/libc
.ERROR_TARGET='libc.so.7'
.ERROR_META_FILE='/common/S4/obj/usr/src/lib/libc/libc.so.7.meta'
.MAKE.LEVEL='4'
MAKEFILE=''
.MAKE.MODE='meta missing-filemon=yes missing-meta=yes silent=yes verbose'
.CURDIR='/usr/src/lib/libc'
.MAKE='/usr/obj/usr/src/make.amd64/bmake'
.OBJDIR='/usr/obj/usr/src/lib/libc'
.TARGETS='all'
DESTDIR='/usr/obj/usr/src/tmp'
LD_LIBRARY_PATH=''
MACHINE='amd64'
MACHINE_ARCH='amd64'

....

Any suggestions?

Thanks!

Peace,
david
-- 
David H. Wolfskill				david_at_catwhisker.org
"[T]he president’s improper efforts to influence an ongoing investigation"

See http://www.catwhisker.org/~david/publickey.gpg for my public key.