build world from ccache broken after > r284345

Hi.

I have next problem:

root_at_nonamehost:/usr/src # make -j5 buildworld kernel
--- buildworld ---
--- buildworld_prologue ---
--------------------------------------------------------------
>>> World build started on Fri Jun 19 10:43:22 EEST 2015
--------------------------------------------------------------
--- _worldtmp ---
--------------------------------------------------------------
>>> Rebuilding the temporary build tree
--------------------------------------------------------------
rm -rf /media/da0s1/obj/usr/src/tmp
rm -rf /media/da0s1/obj/usr/src/lib32
mkdir -p /media/da0s1/obj/usr/src/tmp/lib
mkdir -p /media/da0s1/obj/usr/src/tmp/usr
mkdir -p /media/da0s1/obj/usr/src/tmp/legacy/bin
mkdir -p /media/da0s1/obj/usr/src/tmp/legacy/usr
mtree -deU -f /usr/src/etc/mtree/BSD.usr.dist
-p /media/da0s1/obj/usr/src/tmp/legacy/usr >/dev/null mtree -deU
-f /usr/src/etc/mtree/BSD.groff.dist
-p /media/da0s1/obj/usr/src/tmp/legacy/usr >/dev/null mtree -deU
-f /usr/src/etc/mtree/BSD.usr.dist  -p /media/da0s1/obj/usr/src/tmp/usr
>/dev/null mtree -deU -f /usr/src/etc/mtree/BSD.include.dist
>-p /media/da0s1/obj/usr/src/tmp/usr/include >/dev/null ln
>-sf /usr/src/sys /media/da0s1/obj/usr/src/tmp --- _legacy ---
--------------------------------------------------------------
>>> stage 1.1: legacy release compatibility shims
--------------------------------------------------------------
cd /usr/src; MAKEOBJDIRPREFIX=/media/da0s1/obj/usr/src/tmp
INSTALL="sh /usr/src/tools/install.sh"
PATH=/media/da0s1/obj/usr/src/tmp/legacy/usr/sbin:/media/da0s1/obj/usr/src/tmp/legacy/usr/bin:/media/da0s1/obj/usr/src/tmp/legacy/bin:/sbin:/bin:/usr/sbin:/usr/bin
WORLDTMP=/media/da0s1/obj/usr/src/tmp  VERSION="FreeBSD 11.0-CURRENT
amd64 1100077"  MAKEFLAGS="-m /usr/src/tools/build/mk  -j 5 -J 15,16
-m /usr/src/share/mk" make  -f Makefile.inc1  DESTDIR=
BOOTSTRAPPING=1100077  SSP_CFLAGS=  MK_HTML=no NO_LINT=yes MK_MAN=no
-DNO_PIC MK_PROFILE=no -DNO_SHARED  -DNO_CPU_CFLAGS MK_WARNS=no
MK_CTF=no  MK_CLANG_EXTRAS=no MK_CLANG_FULL=no  MK_LLDB=no MK_TESTS=no
MK_INCLUDES=yes legacy --- legacy --- ===> tools/build
(obj,includes,depend,all,install) --- obj
--- /media/da0s1/obj/usr/src/tmp/usr/src/tools/build created
for /usr/src/tools/build --- includes --- ; cd /usr/src/tools/build;
make buildincludes; make installincludes --- .depend --- rm -f .depend
CC=' ' mkdep -f .depend -a
-I/media/da0s1/obj/usr/src/tmp/legacy/usr/include
-std=gnu99   /usr/src/tools/build/dummy.c /usr/bin/mkdep: -E: not found
mkdep: compile failed *** [.depend] Error code 1

make[3]: stopped in /usr/src/tools/build
1 error

make[3]: stopped in /usr/src/tools/build
A failure has been detected in another branch of the parallel make

make[2]: stopped in /usr/src
*** [_legacy] Error code 2

make[1]: stopped in /usr/src
1 error

make[1]: stopped in /usr/src
*** [buildworld] Error code 2

make: stopped in /usr/src
1 error

make: stopped in /usr/src


For the early revisions of all passed successfully.

For example, on my i386 router the buildworld (after > r284345) with
use time for more than 2 days! Before it takes a few hours.

What should be done, that would be everything as before?

Thanks.