The started failing recently with one src-internal roll in the regression range:

https://ci.chromium.org/p/chromium/builders/luci.chromium.ci/GPU%20FYI%20Linux%20Builder/23678

Error is:

________ running '/b/swarming/w/ir/cache/vpython/998566/bin/python src/chromeos/assistant/internal/build_libassistant.py --sync_only' in '/b/swarming/w/ir/cache/builder'
/b/swarming/w/ir/kitchen-checkout/depot_tools/gclient: line 9: /b/swarming/w/ir/kitchen-checkout/depot_tools/update_depot_tools: No such file or directory
Traceback (most recent call last):
  File "src/chromeos/assistant/internal/build_libassistant.py", line 172, in <module>
    sys.exit(main(sys.argv[1:]))
  File "src/chromeos/assistant/internal/build_libassistant.py", line 99, in main
    cwd=os.path.join(libassistant_standalone_path, 'src'))
  File "/b/swarming/w/ir/cipd_bin_packages/lib/python2.7/subprocess.py", line 186, in check_call
    raise CalledProcessError(retcode, cmd)
subprocess.CalledProcessError: Command '['gclient', 'sync', '-j32']' returned non-zero exit status 127

Not sure if I have the permissions to revert things in the right repos but I'll give it a try. CC'ing troopers in case they need to look on Monday.