The "test_pre_run" step is going purple for "angle_end2end_tests"; seems to be a sharding error?

  File "C:\b\swarming\w\ir\cache\builder\src\testing\trigger_scripts\trigger_multiple_dimensions.py", line 162, in <module>
    sys.exit(main())
  File "C:\b\swarming\w\ir\cache\builder\src\testing\trigger_scripts\trigger_multiple_dimensions.py", line 158, in main
    return triggerer.trigger_tasks(args, remaining)
  File "C:\b\swarming\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 "C:\b\swarming\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 "C:\b\swarming\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 "C:\b\swarming\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 "C:\b\swarming\w\ir\cipd_bin_packages\bin\Lib\random.py", line 242, in randint
    return self.randrange(a, b+1)
  File "C:\b\swarming\w\ir\cipd_bin_packages\bin\Lib\random.py", line 218, in randrange
    raise ValueError, "empty range for randrange() (%d,%d, %d)" % (istart, istop, width)
ValueError: empty range for randrange() (1,1, 0)

My fault. I put the alternate swarming dimensions slightly off in my CL here: https://crrev.com/c/1406083

Should be 10de:1cb3-24.21.14.1195 and I put 10de:1cb3-23.21.14.1195 for the upgraded Windows 7 driver.

I'll fix it ASAP.

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/427999cfc3d0da1500edf93898f497ad0e8a91bb

commit 427999cfc3d0da1500edf93898f497ad0e8a91bb
Author: Jamie Madill <jmadill@chromium.org>
Date: Fri Jan 18 16:14:31 2019

Update Win7 NVIDIA bot driver dimensions.

This removes the alternate dimensions now that the driver upgrade
is complete. It also fixes the dimensions. The should have used the
number 24.21.14.1195 instead of 23.21.14.1195.

Bug:  923323 
Bug: 887241
Change-Id: I946ee2a2e04b35f9437849162005859dd1eb6fb6
Tbr: kbr@chromium.org
Reviewed-on: https://chromium-review.googlesource.com/c/1421877
Reviewed-by: Jamie Madill <jmadill@chromium.org>
Commit-Queue: Jamie Madill <jmadill@chromium.org>
Cr-Commit-Position: refs/heads/master@{#624148}
[modify] https://crrev.com/427999cfc3d0da1500edf93898f497ad0e8a91bb/testing/buildbot/chromium.gpu.fyi.json
[modify] https://crrev.com/427999cfc3d0da1500edf93898f497ad0e8a91bb/testing/buildbot/mixins.pyl
[modify] https://crrev.com/427999cfc3d0da1500edf93898f497ad0e8a91bb/testing/buildbot/waterfalls.pyl

Issue 923232 has been merged into this issue.

Bot has recovered: https://ci.chromium.org/p/chromium/builders/luci.chromium.ci/Win7%20FYI%20Release%20%28NVIDIA%29/3996