Failed to biild world in r342545

[Mitya]

12.0-STABLE FreeBSD 12.0-STABLE r341991 GENERIC  amd64

1 trouble.

Part of "mount -v"

tmpfs on /tmp (tmpfs, local)
/tmp/obj on /usr/obj (nullfs, local)

/usr/src# make -j 8 buildworld && make installworld

installing DIRS BINDIR
install  -d -m 0755 -o root  -g wheel  /boot
objcopy -S -O binary boot1.out boot1
objcopy -S -O binary boot2.out boot2.bin
btxld -v -E 0x2000 -f bin -b 
/usr/obj/usr/src/amd64.amd64/stand/i386/btx/btx/btx -l boot2.ldr -o 
boot2.ld -P 1 boot2.bin
make[6]: exec(btxld) failed (No such file or directory)
*** Error code 1

Also not founding `ls`, `dd` and `xz`. Adding them into this list in 
/usr/src/Makefile.inc1solve problem:

ITOOLS= [ awk cap_mkdb cat chflags chmod chown cmp cp \
         date echo egrep find grep id install ${_install-info} \
         ln make mkdir mtree mv pwd_mkdb \
         rm sed services_mkdb sh sort strip sysctl test true uname wc 
${_zoneinfo} \
         ${LOCAL_ITOOLS}


2 trouble.

Part of "mount -v"

tmpfs on /tmp (tmpfs, local)

/tmp/obj - ordinary directory

/usr/src# make -j 8 buildworld MAKEOBJDIRPREFIX=/tmp/obj

gzip -cn /usr/src/share/man/man4/tap.4 > tap.4.gz
--- all_subdir_rescue ---
cc: error: no such file or directory: 
'/tmp/obj/usr/src/rescue/rescue//usr/src/bin/cat/cat.o'
--- all_subdir_usr.bin ---
--- .depend ---


If I build and install sources on same hard disk - all ok