Chrome Version: 57.0.2950.0
Chrome OS Version: 9079.0 developer-build       
Chrome OS Platform: daisy
Network info: 

Please specify Cr-* of the system to which this bug/feature applies (add
the label below).
Build-Toolchain

I've noticed that it used to be possible to run `ebuild-daisy /mnt/host/source/src/third_party/chromiumos-overlay/sys-libs/glibc/glibc-2.19-r13.ebuild clean compile` to get a freshly-compiled glibc, but this currently fails to build due to an autoconf error (see attached build.log):

checking version of armv7a-cros-linux-gnueabi-clang  -B/build/veyron_jerry/tmp/portage/sys-libs/glibc-2.19-r13/temp/bfd-linker... 3.9.0, bad

The issue stems from the ./configure script finding Clang instead of GCC during setup, and interpreting the Clang version as an old version of GCC. Bisecting the tree, I found the following commit that starts causing the issue:

commit 980af0a2ccdd3489edf5cb59dc1998eb32066ee8
Author: Yunlian Jiang <yunlian@google.com>
Date:   Thu Nov 17 13:01:31 2016 -0800
    profile: set the default compiler to LLVM for arm-boards.

    This sets the default compiler to LLVM for arm-boards.
    We have finished the performance test and correctness test
    on different types of amd64 boards.
    BUG= chromium:537368 
    TEST=cros_sdk --boostrap
         cbuild_board peppy-release
 
    Change-Id: I2502d80d42bc408a42dae53f6a18c5f63d9f48a7
    Reviewed-on: https://chromium-review.googlesource.com/412303
    Commit-Ready: Yunlian Jiang <yunlian@chromium.org>
    Tested-by: Yunlian Jiang <yunlian@chromium.org>
    Reviewed-by: Ting-Yuan Huang <laszio@chromium.org>
 
I've currently tried:
1) Inserting cros_use_gcc inserted into config/env/sys-libs/glibc and into the ebuild
2) Adding CC=armv7a-cros-linux-gnueabi-gcc to EXTRA_ECONF within the ebuild - gives the correct compiler, but it tries to use the gold linker instead of the bfd linker. Adding the bfd linker inside a -B flag alongside CC seems not to work. tc-ld-disable-gold also has no effect.
3) Using USE=-clang before the ebuild command.

The upcoming commit of https://chromium-review.googlesource.com/#/c/339261/ also seems to be affected by this problem.