gclient failure (go/cit-pm-49) likely caused corrupt slave checkouts.

Sample log:

build/third_party/gsutil/boto (ERROR)
----------------------------------------
[0:00:03] Started.
_____ build/third_party/gsutil/boto at 98fc59a5896f4ea990a4d527548204fed8f06c64

________ running 'git -c core.deltaBaseCacheLimit=2g clone --no-checkout --progress --verbose https://chromium.googlesource.com/external/boto.git /b/build/third_party/gsutil/_gclient_boto_Fnr7sE' in '/b'
[0:00:03] Cloning into '/b/build/third_party/gsutil/_gclient_boto_Fnr7sE'...
[0:00:03] POST git-upload-pack (196 bytes)
[ click to hide the rest of the message ]
[0:00:03] remote: Short term bandwidth rate limit exceeded for 182615506979@project.gserviceaccount.com
[0:00:03] fatal: protocol error: bad pack header

________ running 'git -c core.deltaBaseCacheLimit=2g clone --no-checkout --progress --verbose https://chromium.googlesource.com/external/boto.git /b/build/third_party/gsutil/_gclient_boto_Fnr7sE' in '/b'
[0:00:03] Cloning into '/b/build/third_party/gsutil/_gclient_boto_Fnr7sE'...
[0:00:04] POST git-upload-pack (196 bytes)
[0:00:04] remote: Short term bandwidth rate limit exceeded for 182615506979@project.gserviceaccount.com
[0:00:04] fatal: protocol error: bad pack header

________ running 'git -c core.deltaBaseCacheLimit=2g clone --no-checkout --progress --verbose https://chromium.googlesource.com/external/boto.git /b/build/third_party/gsutil/_gclient_boto_Fnr7sE' in '/b'
[0:00:05] Cloning into '/b/build/third_party/gsutil/_gclient_boto_Fnr7sE'...
[0:00:05] POST git-upload-pack (196 bytes)
[0:00:05] remote: Short term bandwidth rate limit exceeded for 182615506979@project.gserviceaccount.com
[0:00:05] fatal: protocol error: bad pack header

________ running 'git -c core.deltaBaseCacheLimit=2g clone --no-checkout --progress --verbose https://chromium.googlesource.com/external/boto.git /b/build/third_party/gsutil/_gclient_boto_Fnr7sE' in '/b'
[0:00:07] Cloning into '/b/build/third_party/gsutil/_gclient_boto_Fnr7sE'...
[0:00:07] POST git-upload-pack (196 bytes)
[0:00:07] remote: Short term bandwidth rate limit exceeded for 182615506979@project.gserviceaccount.com
[0:00:07] fatal: protocol error: bad pack header
Traceback (most recent call last):
  File "/b/depot_tools/gclient_scm.py", line 908, in _Clone
    self._Run(clone_cmd, options, cwd=self._root_dir, retry=True)
  File "/b/depot_tools/gclient_scm.py", line 1197, in _Run
    gclient_utils.CheckCallAndFilterAndHeader(cmd, env=env, **kwargs)
  File "/b/depot_tools/gclient_utils.py", line 303, in CheckCallAndFilterAndHeader
    return CheckCallAndFilter(args, **kwargs)
  File "/b/depot_tools/gclient_utils.py", line 549, in CheckCallAndFilter
    rv, args, kwargs.get('cwd', None), None, None)
CalledProcessError: Command 'git -c core.deltaBaseCacheLimit=2g clone --no-checkout --progress --verbose https://chromium.googlesource.com/external/boto.git /b/build/third_party/gsutil/_gclient_boto_Fnr7sE' returned non-zero exit status 128 in /b
----------------------------------------
Traceback (most recent call last):
  File "/b/build/../depot_tools/gclient.py", line 2336, in <module>

build_internal/scripts/slave/mediator (Elapsed: 0:00:00)
----------------------------------------
[0:00:11] Started.
_____ build_internal/scripts/slave/mediator at refs/remotes/origin/master
[0:00:11] Fetching origin

________ running 'git -c core.deltaBaseCacheLimit=2g fetch origin --prune --verbose' in '/b/build_internal/scripts/slave/mediator'
[0:00:12] From https://chrome-internal.googlesource.com/testing-infra-internal
[0:00:12]  = [up to date]      master     -> origin/master

________ running 'git reset --hard HEAD' in '/b/build_internal/scripts/slave/mediator'
[0:00:12] HEAD is now at fb77879 Allow empty response on mediator deletion.
Checked out revision fb778794db4108e255be8f03af37dfa711a22557
[0:00:12] Finished.
----------------------------------------
    sys.exit(main(sys.argv[1:]))
  File "/b/build/../depot_tools/gclient.py", line 2322, in main
    return dispatcher.execute(OptionParser(), argv)
  File "/b/depot_tools/subcommand.py", line 252, in execute
    return command(parser, args[1:])
  File "/b/build/../depot_tools/gclient.py", line 2071, in CMDsync
    ret = client.RunOnDeps('update', args)
  File "/b/build/../depot_tools/gclient.py", line 1385, in RunOnDeps
    work_queue.flush(revision_overrides, command, args, options=self._options)
  File "/b/depot_tools/gclient_utils.py", line 1048, in run
    self.item.run(*self.args, **self.kwargs)
  File "/b/build/../depot_tools/gclient.py", line 789, in run
    file_list)
  File "/b/depot_tools/gclient_scm.py", line 156, in RunCommand
    return getattr(self, command)(options, args, file_list)
  File "/b/depot_tools/gclient_scm.py", line 438, in update
    self._Clone(revision, url, options)
  File "/b/depot_tools/gclient_scm.py", line 916, in _Clone
    if os.listdir(tmp_dir):
OSError: [Errno 2] No such file or directory: '/b/build/third_party/gsutil/_gclient_boto_Fnr7sE'

@@@STEP_TEXT@gclient sync failed!@@@

@@@STEP_EXCEPTION@@@

@@@STEP_CURSOR update_scripts@@@