>>> Configuring source in /var/tmp/portage/www-client/chromium-64.0.3282.85/work/chromium-64.0.3282.85 ...
 * strip-flags: CFLAGS: changed '-O2 -pipe -march=native -fomit-frame-pointer' to '-O2 -pipe -march=native'
 * strip-flags: CXXFLAGS: changed '-O2 -pipe -march=native -fomit-frame-pointer' to '-O2 -pipe -march=native'
 * Configuring bundled ffmpeg...
System information:
Host OS       : linux
Target OS     : linux
Host arch     : x64
Target arch   : x64
Parallel jobs : 8

Chromium skipped
Chrome configure/build:
Running /var/tmp/portage/www-client/chromium-64.0.3282.85/work/chromium-64.0.3282.85/third_party/ffmpeg/configure
 --disable-everything
 --disable-all
 --disable-doc
 --disable-htmlpages
 --disable-manpages
 --disable-podpages
 --disable-txtpages
 --disable-static
 --enable-avcodec
 --enable-avformat
 --enable-avutil
 --enable-fft
 --enable-rdft
 --enable-static
 --enable-libopus
 --disable-bzlib
 --disable-error-resilience
 --disable-iconv
 --disable-lzo
 --disable-network
 --disable-schannel
 --disable-sdl2
 --disable-symver
 --disable-xlib
 --disable-zlib
 --disable-securetransport
 --disable-faan
 --disable-alsa
 --disable-autodetect
 --enable-decoder=vorbis,libopus,flac
 --enable-decoder=pcm_u8,pcm_s16le,pcm_s24le,pcm_s32le,pcm_f32le,mp3
 --enable-decoder=pcm_s16be,pcm_s24be,pcm_mulaw,pcm_alaw
 --enable-demuxer=ogg,matroska,wav,flac,mp3,mov
 --enable-parser=opus,vorbis,flac,mpegaudio
 --extra-cflags=-I/var/tmp/portage/www-client/chromium-64.0.3282.85/work/chromium-64.0.3282.85/third_party/opus/src/include
 --disable-linux-perf
 --x86asmexe=yasm
 --optflags="-O2"
 --enable-decoder=theora,vp8
 --enable-parser=vp3,vp8
 --enable-lto
 --enable-pic
 --cc=clang
 --cxx=clang++
 --ld=clang
 --extra-ldflags=-fuse-ld=lld
 --enable-decoder=aac,h264
 --enable-demuxer=aac
 --enable-parser=aac,h264
clang is unable to create an executable file.
If clang is a cross-compiler, use the --enable-cross-compile option.
Only do this if you know what cross compiling means.
C compiler test failed.

If you think configure made a mistake, make sure you are using the latest
version from Git.  If the latest version fails, report the problem to the
ffmpeg-user@ffmpeg.org mailing list or IRC #ffmpeg on irc.freenode.net.
Include the log file "ffbuild/config.log" produced by configure as this will help
solve the problem.
Traceback (most recent call last):
  File "chromium/scripts/build_ffmpeg.py", line 761, in <module>
    sys.exit(main(sys.argv[1:]))
  File "chromium/scripts/build_ffmpeg.py", line 339, in main
    configure_args, options=options)
  File "chromium/scripts/build_ffmpeg.py", line 741, in ConfigureAndBuild
    configure_flags['Common'] + configure_flags['Chrome'] + configure_args)
  File "chromium/scripts/build_ffmpeg.py", line 733, in do_build_ffmpeg
    options.config_only, branding, configure_flags)
  File "chromium/scripts/build_ffmpeg.py", line 216, in BuildFFmpeg
    [os.path.join(FFMPEG_DIR, 'configure')] + configure_flags, cwd=config_dir)
  File "chromium/scripts/build_ffmpeg.py", line 93, in PrintAndCheckCall
    subprocess.check_call(argv, *args, **kwargs)
  File "/usr/lib64/python2.7/subprocess.py", line 186, in check_call
    raise CalledProcessError(retcode, cmd)
subprocess.CalledProcessError: Command '['/var/tmp/portage/www-client/chromium-64.0.3282.85/work/chromium-64.0.3282.85/third_party/ffmpeg/configure', '--disable-everything', '--disable-all', '--disable-doc', '--disable-htmlpages', '--disable-manpages', '--disable-podpages', '--disable-txtpages', '--disable-static', '--enable-avcodec', '--enable-avformat', '--enable-avutil', '--enable-fft', '--enable-rdft', '--enable-static', '--enable-libopus', '--disable-bzlib', '--disable-error-resilience', '--disable-iconv', '--disable-lzo', '--disable-network', '--disable-schannel', '--disable-sdl2', '--disable-symver', '--disable-xlib', '--disable-zlib', '--disable-securetransport', '--disable-faan', '--disable-alsa', '--disable-autodetect', '--enable-decoder=vorbis,libopus,flac', '--enable-decoder=pcm_u8,pcm_s16le,pcm_s24le,pcm_s32le,pcm_f32le,mp3', '--enable-decoder=pcm_s16be,pcm_s24be,pcm_mulaw,pcm_alaw', '--enable-demuxer=ogg,matroska,wav,flac,mp3,mov', '--enable-parser=opus,vorbis,flac,mpegaudio', '--extra-cflags=-I/var/tmp/portage/www-client/chromium-64.0.3282.85/work/chromium-64.0.3282.85/third_party/opus/src/include', '--disable-linux-perf', '--x86asmexe=yasm', '--optflags="-O2"', '--enable-decoder=theora,vp8', '--enable-parser=vp3,vp8', '--enable-lto', '--enable-pic', '--cc=clang', '--cxx=clang++', '--ld=clang', '--extra-ldflags=-fuse-ld=lld', '--enable-decoder=aac,h264', '--enable-demuxer=aac', '--enable-parser=aac,h264']' returned non-zero exit status 1