Maybe the step should go purple?  It looks like SoM might ignore exceptions.  But having a tree full of purple isn't much better than a tree full of red.

Another alternative is to copy logs in a separate step and exclude that from the gatekeeper configs.

I can make it purple if we fail to copy test data off the device but the test succeeds, but I think house_arrest is usually indicative of a bigger problem with the device and the device should probably be restarted anyway before the test itself stops launching.

Can we / should we take the device out of the swarming pool when this happens?

The device I'm looking at now (build36-b7) consistently failed every device test once it entered this state, but I don't know if that is always true.

Making it purple as in #2 will implicitly take it out of the pool, so sure.

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/4c948f45780a4dbdd9b3fac209b72977d407953b

commit 4c948f45780a4dbdd9b3fac209b72977d407953b
Author: smut <smut@google.com>
Date: Mon Jan 09 21:31:12 2017

Raise an exception if test data or crash reports can't be copied off a device

BUG= 678995 

Review-Url: https://codereview.chromium.org/2618163002
Cr-Commit-Position: refs/heads/master@{#442355}

[modify] https://crrev.com/4c948f45780a4dbdd9b3fac209b72977d407953b/ios/build/bots/scripts/test_runner.py