https://cros-goldeneye.corp.google.com/chromeos/healthmonitoring/buildDetails?buildbucketId=8930482704423603136

NFO    cros_sdk:make_chroot: Updating preinstalled build tools
env: ccache: No such file or directory
Traceback (most recent call last):
  File "/mnt/host/source/chromite/bin/parallel_emerge", line 77, in <module>
    from chromite.lib import commandline
  File "/mnt/host/source/chromite/bin/parallel_emerge", line 69, in load_module
    return __import__(mod)
  File "/mnt/host/source/chromite/__init__.py", line 9, in <module>
    import pkg_resources
ImportError: No module named pkg_resources
Running ['/b/swarming/wBHL5LD/ir/cache/cbuild/repository/src/scripts/sdk_lib/make_chroot.sh', '--stage3_path', '/b/swarming/wBHL5LD/ir/cache/cbuild/repository/.cache/sdks/stage3-amd64-2014.09.18.tar.xz', '--chroot', '/b/swarming/wBHL5LD/ir/cache/cbuild/repository/chroot', '--cache_dir', '/b/swarming/wBHL5LD/ir/cache/cbuild/repository/.cache', '--nousepkg'] failed!
13:34:28: ERROR: 
return code: 1; command: /b/swarming/wBHL5LD/ir/cache/cbuild/repository/chromite/bin/cros_sdk --buildbot-log-version --bootstrap --replace '--chrome_root=/b/swarming/wBHL5LD/ir/cache/cbuild/repository/.cache/distfiles/target-master/chrome-src'
cmd=['/b/swarming/wBHL5LD/ir/cache/cbuild/repository/chromite/bin/cros_sdk', '--buildbot-log-version', '--bootstrap', '--replace', '--chrome_root=/b/swarming/wBHL5LD/ir/cache/cbuild/repository/.cache/distfiles/target-master/chrome-src'], cwd=/b/swarming/wBHL5LD/ir/cache/cbuild/repository, extra env={'FEATURES': 'separatedebug', 'CHROME_ORIGIN': 'LOCAL_SOURCE'}



This looks like a common issue where an ebuild that should have EAPI=5 was submitted with EAPI=6.