# Activates autoenv or reports its failure
  if ! source $HOME/.autoenv/activate.sh 2>/dev/null; then
    echo '-------- AUTOENV ---------'
    echo 'Could not find ~/.autoenv/activate.sh.'
    echo 'Please check if autoenv is correctly installed.'
    echo 'In the meantime the autoenv plugin is DISABLED.'
    echo '--------------------------'
    return 1
  fi
  
  # The use_env call below is a reusable command to activate/create a new Python
  # virtualenv, requiring only a single declarative line of code in your .env files.
  # It only performs an action if the requested virtualenv is not the current one.
  
  use_env() {
      typeset venv
      venv="$1"
      if [[ "${VIRTUAL_ENV:t}" != "$venv" ]]; then
          if workon | grep -q "$venv"; then
              workon "$venv"
          else
              echo -n "Create virtualenv $venv now? (Yn) "
              read answer
              if [[ "$answer" == "Y" ]]; then
                  mkvirtualenv "$venv"
              fi
          fi
      fi
  }