Version: chromium master at commit eb42922e8a7206ee62806d05b8fb736fbae3e18f
OS: Linux
Architecture: ppc64 / ppc64le

$ uname -a
Linux ubuntu14 4.4.0-131-generic #157~14.04.1-Ubuntu SMP Fri Jul 13 08:53:13 UTC 2018 ppc64le ppc64le ppc64le GNU/Linux

What steps will reproduce the problem?
1. fetch chromium


What do you see instead?
Syncing projects: 100% (98/98), done.                                                        
Running hooks:   5% ( 4/75) nacltools
________ running '/usr/local/bin/python src/build/download_nacl_toolchains.py --mode nacl_core_sdk sync --extract' in '/home/user/chromium'
Traceback (most recent call last):
  File "src/build/download_nacl_toolchains.py", line 59, in <module>
    sys.exit(Main(sys.argv[1:]))
  File "src/build/download_nacl_toolchains.py", line 55, in Main
    return package_version.main(args)
  File "/home/user/chromium/src/native_client/build/package_version/package_version.py", line 1288, in main
    arguments = ParseArgs(args)
  File "/home/user/chromium/src/native_client/build/package_version/package_version.py", line 1116, in ParseArgs
    host_arch = pynacl.platform.GetArch3264()
  File "/home/user/chromium/src/native_client/pynacl/platform.py", line 133, in GetArch3264
    assert machine in ARCH3264_DICT, "Unrecognized arch machine: %s" % machine
AssertionError: Unrecognized arch machine: ppc64le
Error: Command '/usr/local/bin/python src/build/download_nacl_toolchains.py --mode nacl_core_sdk sync --extract' returned non-zero exit status 1 in /home/user/chromium

As told on https://bugs.chromium.org/p/chromium/issues/detail?id=871084#c12
I'm mostly opening this to track progress

Thank you