more details?

logs? 

This usually happens because the configure step gets confused .. Can you do the configure step without the BISECT_STAGE on? 
cmtice did this last time... so you can check with her.

From the log, it seems that it did not link a binary.

 /build/terra/tmp/portage/sys-apps/busybox-1.26.2-r1/work/busybox-1.26.2/scripts/trylink "busybox_unstripped" "x86_64-cros-linux-gnu-gcc" "-O2 -pipe -O2 -pipe -march=corei7 -g -fno-exceptions -fno-unwind-tables   -fno-asynchronous-unwind-tables  -clang-syntax -fno-strict-aliasing -Wall -Wshadow -Wwrite-strings -Wundef -Wstrict-prototypes -Wunused -Wunused-parameter -Wunused-function -Wunused-value -Wmissing-prototypes -Wmissing-declarations -Wno-format-security -Wdeclaration-after-statement -Wold-style-definition -fno-builtin-strlen -finline-limit=0 -ffunction-sections -fdata-sections -fno-guess-branch-probability -funsigned-char   -fno-unwind-tables -fno-asynchronous-unwind-tables -fno-builtin-printf    -static" "-Wl,-O1 -Wl,-O2 -Wl,--as-needed  " " applets/built-in.o" " archival/lib.a  archival/libarchive/lib.a  console-tools/lib.a  coreutils/lib.a  coreutils/libcoreutils/lib.a  debianutils/lib.a  e2fsprogs/lib.a  editors/lib.a  findutils/lib.a  init/lib.a  libbb/lib.a  libpwdgrp/lib.a  loginutils/lib.a  mailutils/lib.a  miscutils/lib.a  modutils/lib.a  networking/lib.a  networking/libiproute/lib.a  networking/udhcp/lib.a  printutils/lib.a  procps/lib.a  runit/lib.a  selinux/lib.a  shell/lib.a  sysklogd/lib.a  util-linux/lib.a  util-linux/volume_id/lib.a  archival/built-in.o  archival/libarchive/built-in.o  console-tools/built-in.o  coreutils/built-in.o  coreutils/libcoreutils/built-in.o  debianutils/built-in.o  e2fsprogs/built-in.o  editors/built-in.o  findutils/built-in.o  init/built-in.o  libbb/built-in.o  libpwdgrp/built-in.o  loginutils/built-in.o  mailutils/built-in.o  miscutils/built-in.o  modutils/built-in.o  networking/built-in.o  networking/libiproute/built-in.o  networking/udhcp/built-in.o  printutils/built-in.o  procps/built-in.o  runit/built-in.o  selinux/built-in.o  shell/built-in.o  sysklogd/built-in.o  util-linux/built-in.o  util-linux/volume_id/built-in.o" " m crypt " && /build/terra/tmp/portage/sys-apps/busybox-1.26.2-r1/work/busybox-1.26.2/scripts/generate_BUFSIZ.sh --post include/common_bufsiz.h
Static linking against glibc, can't use --gc-sections
Trying libraries: crypt m
 Library crypt is not needed, excluding it
 Library m is not needed, excluding it
Final link with: <none>
echo 'cmd_busybox_unstripped := /build/terra/tmp/portage/sys-apps/busybox-1.26.2-r1/work/busybox-1.26.2/scripts/trylink "busybox_unstripped" "x86_64-cros-linux-gnu-gcc" "-O2 -pipe -O2 -pipe -march=corei7 -g -fno-exceptions -fno-unwind-tables   -fno-asynchronous-unwind-tables  -clang-syntax -fno-strict-aliasing -Wall -Wshadow -Wwrite-strings -Wundef -Wstrict-prototypes -Wunused -Wunused-parameter -Wunused-function -Wunused-value -Wmissing-prototypes -Wmissing-declarations -Wno-format-security -Wdeclaration-after-statement -Wold-style-definition -fno-builtin-strlen -finline-limit=0 -ffunction-sections -fdata-sections -fno-guess-branch-probability -funsigned-char   -fno-unwind-tables -fno-asynchronous-unwind-tables -fno-builtin-printf    -static" "-Wl,-O1 -Wl,-O2 -Wl,--as-needed  " " applets/built-in.o" " archival/lib.a  archival/libarchive/lib.a  console-tools/lib.a  coreutils/lib.a  coreutils/libcoreutils/lib.a  debianutils/lib.a  e2fsprogs/lib.a  editors/lib.a  findutils/lib.a  init/lib.a  libbb/lib.a  libpwdgrp/lib.a  loginutils/lib.a  mailutils/lib.a  miscutils/lib.a  modutils/lib.a  networking/lib.a  networking/libiproute/lib.a  networking/udhcp/lib.a  printutils/lib.a  procps/lib.a  runit/lib.a  selinux/lib.a  shell/lib.a  sysklogd/lib.a  util-linux/lib.a  util-linux/volume_id/lib.a  archival/built-in.o  archival/libarchive/built-in.o  console-tools/built-in.o  coreutils/built-in.o  coreutils/libcoreutils/built-in.o  debianutils/built-in.o  e2fsprogs/built-in.o  editors/built-in.o  findutils/built-in.o  init/built-in.o  libbb/built-in.o  libpwdgrp/built-in.o  loginutils/built-in.o  mailutils/built-in.o  miscutils/built-in.o  modutils/built-in.o  networking/built-in.o  networking/libiproute/built-in.o  networking/udhcp/built-in.o  printutils/built-in.o  procps/built-in.o  runit/built-in.o  selinux/built-in.o  shell/built-in.o  sysklogd/built-in.o  util-linux/built-in.o  util-linux/volume_id/built-in.o" " m crypt " && /build/terra/tmp/portage/sys-apps/busybox-1.26.2-r1/work/busybox-1.26.2/scripts/generate_BUFSIZ.sh --post include/common_bufsiz.h' > ./.busybox_unstripped.cmd
rm -f .old_version
cp busybox_unstripped busybox
cp: cannot stat 'busybox_unstripped': No such file or directory

It did not create busybox_unstripped