Due to  issue 808434 , we had to push this hack to disable unit tests on ci-results-archiver: https://chromium-review.googlesource.com/c/910610/

We should figure out what's wrong with virtualenv in this case, and reenable the test.

The error happens when running on the -release builder, or when building locally with this line:
VIRTUALENV_ALWAYS_COPY=1 FEATURES=test emerge-elm -av ci-results-archiver

Note that unsetting/unexporting VIRTUALENV_ALWAYS_COPY works for the local repro above, but does _not_ work on the builder, for whatever reason.

Error looks like this:
https://uberchromegw.corp.google.com/i/chromiumos.tryserver/builders/release/builds/19849
ci-results-archiver-0.0.1-r1: >>> Test phase: chromeos-base/ci-results-archiver-0.0.1-r1
ci-results-archiver-0.0.1-r1: Traceback (most recent call last):
ci-results-archiver-0.0.1-r1:   File "/usr/lib/python-exec/python2.7/virtualenv", line 9, in <module>
ci-results-archiver-0.0.1-r1:     load_entry_point('virtualenv==13.1.2', 'console_scripts', 'virtualenv')()
ci-results-archiver-0.0.1-r1:   File "/usr/lib64/python2.7/site-packages/virtualenv.py", line 832, in main
ci-results-archiver-0.0.1-r1:     symlink=options.symlink)
ci-results-archiver-0.0.1-r1:   File "/usr/lib64/python2.7/site-packages/virtualenv.py", line 1004, in create_environment
ci-results-archiver-0.0.1-r1:     install_wheel(to_install, py_executable, search_dirs)
ci-results-archiver-0.0.1-r1:   File "/usr/lib64/python2.7/site-packages/virtualenv.py", line 969, in install_wheel
ci-results-archiver-0.0.1-r1:     'PIP_NO_INDEX': '1'
ci-results-archiver-0.0.1-r1:   File "/usr/lib64/python2.7/site-packages/virtualenv.py", line 910, in call_subprocess
ci-results-archiver-0.0.1-r1:     % (cmd_desc, proc.returncode))
ci-results-archiver-0.0.1-r1: OSError: Command /build/elm/tmp/porta...7d6ff7/bin/python2.7 -c "import sys, pip; sys...d\"] + sys.argv[1:]))" setuptools pip wheel failed with error code 1
ci-results-archiver-0.0.1-r1: Traceback (most recent call last):
ci-results-archiver-0.0.1-r1:   File "/usr/lib64/python2.7/runpy.py", line 162, in _run_module_as_main
ci-results-archiver-0.0.1-r1:     "__main__", fname, loader, pkg_name)
ci-results-archiver-0.0.1-r1:   File "/usr/lib64/python2.7/runpy.py", line 72, in _run_code
ci-results-archiver-0.0.1-r1:     exec code in run_globals
ci-results-archiver-0.0.1-r1:   File "/mnt/host/source/infra_virtualenv/venv/cros_venv/scripts/create_venv.py", line 46, in <module>
ci-results-archiver-0.0.1-r1:     main()
ci-results-archiver-0.0.1-r1:   File "/mnt/host/source/infra_virtualenv/venv/cros_venv/scripts/create_venv.py", line 35, in main
ci-results-archiver-0.0.1-r1:     print(venv.ensure())
ci-results-archiver-0.0.1-r1:   File "/mnt/host/source/infra_virtualenv/venv/cros_venv/venvlib.py", line 100, in ensure
ci-results-archiver-0.0.1-r1:     self._check_or_create()
ci-results-archiver-0.0.1-r1:   File "/mnt/host/source/infra_virtualenv/venv/cros_venv/venvlib.py", line 108, in _check_or_create
ci-results-archiver-0.0.1-r1:     self._create()
ci-results-archiver-0.0.1-r1:   File "/mnt/host/source/infra_virtualenv/venv/cros_venv/venvlib.py", line 117, in _create
ci-results-archiver-0.0.1-r1:     logfile=logfile)
ci-results-archiver-0.0.1-r1:   File "/mnt/host/source/infra_virtualenv/venv/cros_venv/venvlib.py", line 209, in _create_venv
ci-results-archiver-0.0.1-r1:     _log_check_call(command, logfile=logfile)
ci-results-archiver-0.0.1-r1:   File "/mnt/host/source/infra_virtualenv/venv/cros_venv/venvlib.py", line 254, in wrapped_command
ci-results-archiver-0.0.1-r1:     call_func(args, stdout=logfile, **kwargs)
ci-results-archiver-0.0.1-r1:   File "/usr/lib64/python2.7/subprocess.py", line 540, in check_call
ci-results-archiver-0.0.1-r1:     raise CalledProcessError(retcode, cmd)
ci-results-archiver-0.0.1-r1: subprocess.CalledProcessError: Command '[u'virtualenv', u'/build/elm/tmp/portage/chromeos-base/ci-results-archiver-0.0.1-r1/homedir/.cache/cros_venv/venv-2.7.10-9b73359f13f2cf7b6ed8f86d2c7d6ff7', u'-p', u'/usr/bin/python2.7', u'--extra-search-dir', u'/mnt/host/source/infra_virtualenv/pip_packages', u'--setuptools', u'--clear']' returned non-zero exit status 1
ci-results-archiver-0.0.1-r1: ERROR: Failed to set up a virtualenv.