see https://build.chromium.org/p/chromium.gpu.fyi/builders/Win10%20Release%20%28NVIDIA%20Quadro%20P400%29?numbuilds=200

example build:
https://build.chromium.org/p/chromium.gpu.fyi/builders/Win10%20Release%20%28NVIDIA%20Quadro%20P400%29/builds/836

update_scripts update_scripts
gclient sync failed!

Traceback (most recent call last):
  File "C:\b\build\scripts\slave\update_scripts.py", line 144, in update_scripts
    rv, out = get_repo_head(path)
  File "C:\b\build\scripts\slave\update_scripts.py", line 69, in get_repo_head
    return _run_command(cmd, cwd=path, stdout=subprocess.PIPE)
  File "C:\b\build\scripts\slave\update_scripts.py", line 31, in _run_command
    proc = subprocess.Popen(cmd, **kwargs)
  File "C:\b\depot_tools\python276_bin\lib\subprocess.py", line 709, in __init__
    errread, errwrite)
  File "C:\b\depot_tools\python276_bin\lib\subprocess.py", line 957, in _execute_child
    startupinfo)
WindowsError: [Error 2] The system cannot find the file specified
fatal: Not a git repository (or any of the parent directories): .git
fatal: Not a git repository (or any of the parent directories): .git
Failed to update depot_tools.
Looking for .gclient starting from C:\b\build

Loaded .gclient config in C:\b:
solutions = [
  { "name"        : "slave.DEPS",
    "url"         : "https://chrome-internal.googlesource.com/chrome/tools/build/slave.DEPS.git",
    "deps_file"   : ".DEPS.git",
    "managed"     : True,
    "custom_deps" : {
    },
  },
]
cache_dir = None


slave.DEPS
----------------------------------------
[0:00:00] Started.
_____ slave.DEPS at refs/remotes/origin/master
----------------------------------------

slave.DEPS (ERROR)
----------------------------------------
[0:00:00] Started.
_____ slave.DEPS at refs/remotes/origin/master
----------------------------------------
Error: Command 'git remote --verbose update' returned non-zero exit status 1 in C:\b\slave.DEPS
error: bad signature
fatal: index file corrupt

Assigning to current pixel wrangler, vmpstr.