Community Issues Reference Playground

Tree Sheriffs Documentation


What does a sheriff do?

A sheriff keeps an eye on the tree, DEPS rolls, Gold tool and the Perf tool.

Below is a brief summary of what the sheriff does for each task:

Skia tree


If you have Go installed, a command-line tool is available to search through git history and do text searches on the full patch text and the commit message. To install blamer run:

go get

Then run blamer from within a Skia checkout. For example, to search if the string “SkDevice” has appeared in the last 10 commits:

$ $GOPATH/bin/blamer --match SkDevice --num 10

commit ea70c4bb22394c8dcc29a369d3422a2b8f3b3e80
Author: robertphillips <>
Date:   Wed Jul 20 08:54:31 2016 -0700

    Remove SkDevice::accessRenderTarget virtual


DEPS rolls

Gold and Perf


In general, sheriffs should have a strong bias towards actions that keep the tree green and then open; if a simple revert can fix the problem, the sheriff should revert first and ask questions later.

View current and upcoming sheriffs

The list of sheriffs is specified in the skia-tree-status web app. The current sheriff is highlighted in green. The banner on the top of the status page also displays the current sheriff.

How to swap sheriff shifts

If you need to swap shifts with someone (because you are out sick or on vacation), please get approval from the person you want to swap with. Then send an email to to have someone make the database change (or directly ping rmistry@).

Tips for sheriffs

When to file bugs

Pay close attention to the “Failures” view in the status page. Look at all existing BreakingTheBuildbots bugs. If the list is kept up to date then it should accurately represent everything that is causing failures. If it does not, then please file/update bugs accordingly.

How to close or re-open the tree

  1. Go to
  2. Change the status.
    • To close the tree, include the word “closed” in the status.
    • To open the tree, include the word “open” in the status.
    • To caution the tree, include the word “caution” in the status.

How to submit when the tree is closed

How to revert a CL

See the revert documentation here.

What to do if DEPS roll fails to land

A common cause of DEPS roll failures are layout tests. Find the offending Skia CL by examining the commit hash range in the DEPS roll and revert (or talk to the commit author if they are available). If you do revert then keep an eye on the next DEPS roll to make sure it succeeds.

If a Skia CL changes layout tests, but the new images look good, the tests need to be rebaselined. See Rebaseline Layout Tests.

Rebaseline Layout Tests (i.e., add suppressions)