title: Unable to install protobuf in https://colab.research.google.com
body: <p>I am trying to install <code>apt-get install protobuf-compiler python-pil python-lxml</code> in  <a href="https://colab.research.google.com" rel="nofollow noreferrer">https://colab.research.google.com</a>: </p>
  
  <pre><code>Reading package lists... Done
  Building dependency tree       
  Reading state information... Done
  The following additional packages will be installed:
    libjbig0 libjpeg-turbo8 libjpeg8 liblcms2-2 libprotobuf10 libprotoc10
    libtiff5 libwebp6 libwebpmux3 libxslt1.1 python-bs4 python-chardet
    python-html5lib python-olefile python-six python-webencodings
  Suggested packages:
    liblcms2-utils python-genshi python-lxml-dbg python-lxml-doc python-pil-doc
    python-pil-dbg
  The following NEW packages will be installed:
    libjbig0 libjpeg-turbo8 libjpeg8 liblcms2-2 libprotobuf10 libprotoc10
    libtiff5 libwebp6 libwebpmux3 libxslt1.1 protobuf-compiler python-bs4
    python-chardet python-html5lib python-lxml python-olefile python-pil
    python-six python-webencodings
  0 upgraded, 19 newly installed, 0 to remove and 0 not upgraded.
  Need to get 3,734 kB of archives.
  After this operation, 14.6 MB of additional disk space will be used.
  Do you want to continue? [Y/n] 
  </code></pre>
  
  <p>But I am unable to continue by saying <code>Y</code>. </p>