chromium RPi build fail

  -> Found chromium.desktop
  -> Found chromium.default
  -> Found chromium.sh
  -> Found chromium-gcc47.patch
  -> Found sqlite-3.7.6.3-fix-out-of-scope-memory-reference.patch
==> Validating source files with sha256sums...
    chromium-20.0.1132.47.tar.bz2 ... Passed
    naclsdk_linux-20.0.1132.47.tar.bz2 ... Passed
    chromium.desktop ... Passed
    chromium.default ... Passed
    chromium.sh ... Passed
    chromium-gcc47.patch ... Passed
    sqlite-3.7.6.3-fix-out-of-scope-memory-reference.patch ... Passed
==> Extracting Sources...
  -> Extracting chromium-20.0.1132.47.tar.bz2 with bsdtar
  -> Extracting naclsdk_linux-20.0.1132.47.tar.bz2 with bsdtar
==> Starting build()...
patching file base/message_pump_libevent.cc
patching file chrome/browser/policy/policy_path_parser_linux.cc
patching file ipc/ipc_channel.h
Hunk #1 succeeded at 12 (offset 3 lines).
patching file ipc/ipc_platform_file.cc
patching file seccompsandbox/library.h
patching file third_party/sqlite/amalgamation/sqlite3.c
Hunk #1 succeeded at 119149 (offset 117911 lines).
Hunk #2 succeeded at 119187 (offset 117911 lines).
Updating projects from gyp files...
static library third_party/libvpx/libvpx.gyp:libvpx#target has several files with the same basename:
  scalesystemdependent: source/libvpx/vpx_scale/arm/scalesystemdependent.c source/libvpx/vpx_scale/generic/scalesystemdependent.c
Some build systems, e.g. MSVC08, cannot handle that.
Traceback (most recent call last):
  File "build/gyp_chromium", line 173, in <module>
    sys.exit(gyp.main(args))
  File "/home/user/build-tmp/chromium/src/chromium-20.0.1132.47/tools/gyp/pylib/gyp/__init__.py", line 471, in main
    options.circular_check)
  File "/home/user/build-tmp/chromium/src/chromium-20.0.1132.47/tools/gyp/pylib/gyp/__init__.py", line 111, in Load
    depth, generator_input_info, check, circular_check)
  File "/home/user/build-tmp/chromium/src/chromium-20.0.1132.47/tools/gyp/pylib/gyp/input.py", line 2520, in Load
    ValidateSourcesInTarget(target, target_dict, build_file)
  File "/home/user/build-tmp/chromium/src/chromium-20.0.1132.47/tools/gyp/pylib/gyp/input.py", line 2200, in ValidateSourcesInTarget
    raise KeyError, 'Duplicate basenames in sources section, see list above'
KeyError: 'Duplicate basenames in sources section, see list above'
==> ERROR: A failure occurred in build().
    Aborting...