looks like presubmit_support must be executed via vpython and include python-coverage.

i think this was broken since dnj and i decided to exclude python-coverage from the auto-installed CIPD packages.

Seriously, we need to fix this; nearly every CL we're trying to land in the build repo is failing.

Issue 772660 has been merged into this issue.

I threw this together. Instead of building more junk on top of a hack, it trues to actually solve the problem :) https://chromium-review.googlesource.com/#/c/chromium/tools/build/+/706817

dnj leads this

CL has landed, let's see how it did?

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/tools/build/+/e5e872a092f3b5386f593dbe14425cb93f10f737

commit e5e872a092f3b5386f593dbe14425cb93f10f737
Author: Dan Jacques <dnj@chromium.org>
Date: Sat Oct 07 21:59:23 2017

[scripts/slave/unittests] Use "vpython".

Replace the "test_env" hacky coverage bootstrapping with "vpython",
which uses the "coverage" wheel.

BUG= chromium:771731 
TEST=local

Change-Id: I70a8c96654bdb6847cd56b1eb12d6f1a9e132942
Reviewed-on: https://chromium-review.googlesource.com/706817
Commit-Queue: Daniel Jacques <dnj@chromium.org>
Reviewed-by: Nodir Turakulov <nodir@chromium.org>

[modify] https://crrev.com/e5e872a092f3b5386f593dbe14425cb93f10f737/scripts/slave/unittests/chromium_commands_test.py
[modify] https://crrev.com/e5e872a092f3b5386f593dbe14425cb93f10f737/scripts/slave/unittests/test_env.py
[modify] https://crrev.com/e5e872a092f3b5386f593dbe14425cb93f10f737/scripts/slave/unittests/recipe_lint_test.py
[modify] https://crrev.com/e5e872a092f3b5386f593dbe14425cb93f10f737/scripts/slave/unittests/runtest_test.py
[modify] https://crrev.com/e5e872a092f3b5386f593dbe14425cb93f10f737/scripts/slave/unittests/runisolatedtest_test.py
[modify] https://crrev.com/e5e872a092f3b5386f593dbe14425cb93f10f737/scripts/slave/unittests/gatekeeper_ng_test.py
[modify] https://crrev.com/e5e872a092f3b5386f593dbe14425cb93f10f737/scripts/slave/unittests/cipd_package_test.py
[add] https://crrev.com/e5e872a092f3b5386f593dbe14425cb93f10f737/scripts/slave/unittests/.vpython
[modify] https://crrev.com/e5e872a092f3b5386f593dbe14425cb93f10f737/scripts/slave/unittests/infra_platform_test.py
[modify] https://crrev.com/e5e872a092f3b5386f593dbe14425cb93f10f737/scripts/slave/unittests/robust_tempdir_test.py
[modify] https://crrev.com/e5e872a092f3b5386f593dbe14425cb93f10f737/scripts/slave/unittests/recipe_test.py
[modify] https://crrev.com/e5e872a092f3b5386f593dbe14425cb93f10f737/scripts/slave/unittests/filter_compilations_test.py
[modify] https://crrev.com/e5e872a092f3b5386f593dbe14425cb93f10f737/scripts/slave/unittests/slave_utils_test.py
[modify] https://crrev.com/e5e872a092f3b5386f593dbe14425cb93f10f737/scripts/slave/unittests/logdog_bootstrap_test.py
[modify] https://crrev.com/e5e872a092f3b5386f593dbe14425cb93f10f737/scripts/slave/unittests/results_dashboard_test.py
[modify] https://crrev.com/e5e872a092f3b5386f593dbe14425cb93f10f737/DEPS
[modify] https://crrev.com/e5e872a092f3b5386f593dbe14425cb93f10f737/scripts/slave/unittests/performance_log_processor_test.py
[modify] https://crrev.com/e5e872a092f3b5386f593dbe14425cb93f10f737/scripts/slave/unittests/zip_build_test.py
[modify] https://crrev.com/e5e872a092f3b5386f593dbe14425cb93f10f737/scripts/slave/unittests/update_scripts_unittest.py
[modify] https://crrev.com/e5e872a092f3b5386f593dbe14425cb93f10f737/scripts/slave/unittests/bot_update_coverage_test.py
[modify] https://crrev.com/e5e872a092f3b5386f593dbe14425cb93f10f737/scripts/slave/unittests/annotated_run_test.py
[modify] https://crrev.com/e5e872a092f3b5386f593dbe14425cb93f10f737/scripts/slave/unittests/extract_build_test.py
[modify] https://crrev.com/e5e872a092f3b5386f593dbe14425cb93f10f737/PRESUBMIT.py
[modify] https://crrev.com/e5e872a092f3b5386f593dbe14425cb93f10f737/scripts/slave/unittests/build_scan_test.py
[modify] https://crrev.com/e5e872a092f3b5386f593dbe14425cb93f10f737/scripts/slave/unittests/buildrunner_test.py
[modify] https://crrev.com/e5e872a092f3b5386f593dbe14425cb93f10f737/scripts/slave/unittests/package_index_test.py
[modify] https://crrev.com/e5e872a092f3b5386f593dbe14425cb93f10f737/scripts/slave/unittests/utils.py
[modify] https://crrev.com/e5e872a092f3b5386f593dbe14425cb93f10f737/scripts/slave/unittests/gatekeeper_ng_config_test.py
[modify] https://crrev.com/e5e872a092f3b5386f593dbe14425cb93f10f737/scripts/slave/unittests/remote_run_test.py

Hmm looks like I broke "runhooks" ... https://luci-logdog.appspot.com/v/?s=infra%2Fbuildbucket%2Fcr-buildbucket.appspot.com%2F8966355732088214176%2F%2B%2Fsteps%2Fgclient_runhooks%2F0%2Fstdout

Let me figure this out.

Problem was the Mac "coverage" wheel declared via filename that it was OSX 10.10+, and the builder was running on OSX 10.9 and, consequently, refusing to install the wheel.

I hacked a solution by manually renaming the package "10_8", deleting the original CIPD package, re-uploading the new one w/ the renamed file, and purging the CIPD caches on the affected builders.

This solution sucks, but was probably the simplest way to resolve. Really we need to figure out exactly which platforms we support :/