Started recently. Example failing builds:

https://ci.chromium.org/p/chromium/builders/luci.chromium.try/mac_optional_gpu_tests_rel/6440

https://ci.chromium.org/p/chromium/builders/luci.chromium.try/mac_optional_gpu_tests_rel/6447

https://ci.chromium.org/p/chromium/builders/luci.chromium.try/mac_optional_gpu_tests_rel/6471

Exception text:

Traceback (most recent call last):
  File "/b/s/w/ir/cache/builder/src/testing/trigger_scripts/trigger_multiple_dimensions.py", line 134, in <module>
    sys.exit(main())
  File "/b/s/w/ir/cache/builder/src/testing/trigger_scripts/trigger_multiple_dimensions.py", line 130, in main
    return triggerer.trigger_tasks(args, remaining)
  File "/b/s/w/ir/cache/builder/src/testing/trigger_scripts/base_test_triggerer.py", line 246, in trigger_tasks
    selected_configs = self.select_config_indices(args, verbose)
  File "/b/s/w/ir/cache/builder/src/testing/trigger_scripts/trigger_multiple_dimensions.py", line 117, in select_config_indices
    selected_indices.append(self.pick_bot_configuration(verbose))
  File "/b/s/w/ir/cache/builder/src/testing/trigger_scripts/trigger_multiple_dimensions.py", line 105, in pick_bot_configuration
    r = self.choose_random_int(self._total_bots)
  File "/b/s/w/ir/cache/builder/src/testing/trigger_scripts/trigger_multiple_dimensions.py", line 75, in choose_random_int
    return random.randint(1, max_num)
  File "/b/s/w/ir/cipd_bin_packages/lib/python2.7/random.py", line 244, in randint
    return self.randrange(a, b+1)
  File "/b/s/w/ir/cipd_bin_packages/lib/python2.7/random.py", line 220, in randrange
    raise ValueError, "empty range for randrange() (%d,%d, %d)" % (istart, istop, width)
ValueError: empty range for randrange() (1,1, 0)
step returned non-zero exit code: 1

Not sure if this issue is already filed but seems pretty bad. Ken any idea?