@task
def virtualenv_verify(requirements_revision=None):
  req_rev = requirements_revision or latest_requirements_revision()

  env_dir = 'env.%s' % req_rev
  package_dir = 'python-package.%s' % req_rev
  requirements_file = 'prod-requirements.txt.%s' % req_rev
  with settings(warn_only=True):
    out = run('~/%s/viewfinder/bin/pip install -f file://$HOME/%s --no-index -r ~/%s --no-install --no-download -q' % (env_dir, package_dir, requirements_file))
  if out.return_code == 0:
    fprint('Valid virtual environment for prod-requirements (rev %s)' % req_rev)
    return True
  else:
    fprint('Bad virtual environment for prod-requirements (rev %s)' % req_rev)
    return False
returns a list of (ctx, node)
dataset/ETHPy150Open viewfinderco/viewfinder/fabfile.py/virtualenv_verify--crossover with--dataset/ETHPy150Open manahl/mdf/mdf/viewer/frame.py/MDFViewerFrame.GetSelectedContextsAndNodes