The failed run: https://uberchromegw.corp.google.com/i/chromeos/builders/master-paladin/builds/10339

The previous run contained:
https://uberchromegw.corp.google.com/i/chromeos/builders/master-paladin/builds/10338
https://chromium-review.googlesource.com/#/c/328271/

Failure:
cros_setup_toolchains: Unhandled exception:
Traceback (most recent call last):
  File "/mnt/host/source/chromite/bin/cros_setup_toolchains", line 164, in <module>
    commandline.ScriptWrapperMain(FindTarget)
  File "/mnt/host/source/chromite/lib/commandline.py", line 834, in ScriptWrapperMain
    ret = target(argv[1:])
  File "/mnt/host/source/chromite/scripts/cros_setup_toolchains.py", line 1120, in main
    root=root)
  File "/mnt/host/source/chromite/scripts/cros_setup_toolchains.py", line 616, in UpdateToolchains
    if TargetIsInitialized(target):
  File "/mnt/host/source/chromite/scripts/cros_setup_toolchains.py", line 353, in TargetIsInitialized
    for package in GetTargetPackages(target):
  File "/mnt/host/source/chromite/scripts/cros_setup_toolchains.py", line 215, in GetTargetPackages
    return [x for x in conf['crosspkgs'].strip("'").split() if conf[x+'_pn']]
AttributeError: 'list' object has no attribute 'strip'