root@orwell:/usr/src # make test-system-compiler MK_SYSTEM_COMPILER=no
USING_SYSTEM_COMPILER              = no
MK_SYSTEM_COMPILER                 = no
MK_CROSS_COMPILER                  = yes
MK_CLANG_BOOTSTRAP                 = yes
MK_GCC_BOOTSTRAP                   = no
WANT_COMPILER_TYPE                 = clang
WANT_COMPILER_VERSION              = 40000
WANT_COMPILER_VERSION_FILE         = lib/clang/include/clang/Basic/Version.inc
WANT_COMPILER_FREEBSD_VERSION      = 1200006
WANT_COMPILER_FREEBSD_VERSION_FILE = lib/clang/freebsd_cc_version.h
CC                                 = cc
COMPILER_TYPE                      = clang
COMPILER_VERSION                   = 40000
COMPILER_FREEBSD_VERSION           = 1200006
root@orwell:/usr/src # make installworld MK_SYSTEM_COMPILER=no
mkdir -p /tmp/install.64SipHqF
progs=$(for prog in [ awk cap_mkdb cat chflags chmod chown cmp cp  date echo egrep find grep id install   ln make mkdir mtree mv pwd_mkdb  rm sed services_mkdb sh strip sysctl test true uname wc zic tzsetup   makewhatis; do  if progpath=`which $prog`; then  echo $progpath;  else  echo "Required tool $prog not found in PATH." >&2;  exit 1;  fi;  done);  libs=$(ldd -f "%o %p\n" -f "%o %p\n" $progs 2>/dev/null | sort -u |  while read line; do  set -- $line;  if [ "$2 $3" != "not found" ]; then  echo $2;  else  echo "Required library $1 not found." >&2;  exit 1;  fi;  done);  cp $libs $progs /tmp/install.64SipHqF
cp -R ${PATH_LOCALE:-"/usr/share/locale"} /tmp/install.64SipHqF/locale
cd /usr/src; MAKEOBJDIRPREFIX=/usr/obj  MACHINE_ARCH=amd64  MACHINE=amd64  CPUTYPE=ivybridge GROFF_BIN_PATH=/usr/obj/usr/src/tmp/legacy/usr/bin  GROFF_FONT_PATH=/usr/obj/usr/src/tmp/legacy/usr/share/groff_font  GROFF_TMAC_PATH=/usr/obj/usr/src/tmp/legacy/usr/share/tmac CC="cc -target x86_64-unknown-freebsd12.0 --sysroot=/usr/obj/usr/src/tmp -B/usr/obj/usr/src/tmp/usr/bin" CXX="c++  -target x86_64-unknown-freebsd12.0 --sysroot=/usr/obj/usr/src/tmp -B/usr/obj/usr/src/tmp/usr/bin"  CPP="cpp -target x86_64-unknown-freebsd12.0 --sysroot=/usr/obj/usr/src/tmp -B/usr/obj/usr/src/tmp/usr/bin"  AS="as" AR="ar" LD="ld" LLVM_LINK=""  NM=nm OBJCOPY="objcopy"  RANLIB=ranlib STRINGS=  SIZE="size" 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:/tmp/install.64SipHqF  LD_LIBRARY_PATH=/tmp/install.64SipHqF  PATH_LOCALE=/tmp/install.64SipHqF/locale make -f Makefile.inc1    __MAKE_SHELL=/tmp/install.64SipHqF/sh reinstall;  MAKEOBJDIRPREFIX=/usr/obj  MACHINE_ARCH=amd64  MACHINE=amd64  CPUTYPE=ivybridge GROFF_BIN_PATH=/usr/obj/usr/src/tmp/legacy/usr/bin  GROFF_FONT_PATH=/usr/obj/usr/src/tmp/legacy/usr/share/groff_font  GROFF_TMAC_PATH=/usr/obj/usr/src/tmp/legacy/usr/share/tmac CC="cc -target x86_64-unknown-freebsd12.0 --sysroot=/usr/obj/usr/src/tmp -B/usr/obj/usr/src/tmp/usr/bin" CXX="c++  -target x86_64-unknown-freebsd12.0 --sysroot=/usr/obj/usr/src/tmp -B/usr/obj/usr/src/tmp/usr/bin"  CPP="cpp -target x86_64-unknown-freebsd12.0 --sysroot=/usr/obj/usr/src/tmp -B/usr/obj/usr/src/tmp/usr/bin"  AS="as" AR="ar" LD="ld" LLVM_LINK=""  NM=nm OBJCOPY="objcopy"  RANLIB=ranlib STRINGS=  SIZE="size" 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:/tmp/install.64SipHqF  LD_LIBRARY_PATH=/tmp/install.64SipHqF  PATH_LOCALE=/tmp/install.64SipHqF/locale rm -rf /tmp/install.64SipHqF
sh: cc: not found
make[2]: "/usr/src/share/mk/bsd.compiler.mk" line 145: Unable to determine compiler type for CC=cc -target x86_64-unknown-freebsd12.0 --sysroot=/usr/obj/usr/src/tmp-B/usr/obj/usr/src/tmp/usr/bin.  Consider setting COMPILER_TYPE.
*** Error code 1

Stop.
make[1]: stopped in /usr/src
*** Error code 1

Stop.
make: stopped in /usr/src