title: python pip trouble installing from requirements.txt
body: <p>I've had great luck with pip in the past, but working at installing some stuff in a venv on is giving me some headaches.
  I keep getting errors like
      No distributions at all found for somepackage Storing debug log for failure in /root/.pip/pip.log</p>
  
  <pre><code>Could not find any downloads that satisfy the requirement somepackage
  
  Command "python setup.py egg_info" failed with error code 1 in /tmp/pip-build-RjqjFW/psycopg2
  </code></pre>
  
  <p>I know these packages are installed on the main system, but its like they won't work on the venv. How do you all get around this problem? It's been a long day and I just don't understand what the problem is, especially because they work on my local system, they work on the main python install on my remote system, but not in the venv for some crazy reason. Any ideas?</p>
  
  <p>Here is the requirements, I thought it was alittle intense for django, but thats what pip freeze > requirements.txt gave me</p>
  
  <pre><code>Babel==1.3
  Django==1.7.1
  Fabric==1.10.1
  Flask==0.10.1
  Flask-Babel==0.9
  Flask-Login==0.2.11
  Flask-Mail==0.9.1
  Flask-OpenID==1.2.4
  Flask-SQLAlchemy==2.0
  Flask-WTF==0.10.3
  Flask-WhooshAlchemy==0.56
  Jinja2==2.7.3
  MarkupSafe==0.23
  PAM==0.4.2
  Pillow==2.3.0
  Pygments==1.6
  Scrapy==0.24.4
  Sphinx==1.2.2
  Tempita==0.5.2
  WTForms==2.0.1
  Werkzeug==0.9.6
  Whoosh==2.6.0
  adium-theme-ubuntu==0.3.4
  apt-xapian-index==0.45
  argparse==1.2.1
  backports.ssl-match-hostname==3.4.0.2
  blinker==1.3
  boto==2.20.1
  bottle==0.12.7
  certifi==14.05.14
  chardet==2.0.1
  colorama==0.2.5
  command-not-found==0.3
  coverage==3.7.1
  cssselect==0.9.1
  debtagshw==0.1
  decorator==3.4.0
  defer==1.0.6
  dirspec==13.10
  docutils==0.11
  duplicity==0.6.23
  ecdsa==0.11
  flipflop==1.0
  guess-language==0.2
  guppy==0.1.9
  html5lib==0.999
  httplib2==0.8
  ipython==2.3.1
  itsdangerous==0.24
  lockfile==0.8
  lxml==3.3.3
  nose==1.3.4
  numpy==1.8.2
  oauthlib==0.6.1
  oneconf==0.3.7
  paramiko==1.15.2
  pbr==0.10.7
  pexpect==3.1
  piston-mini-client==0.7.5
  psycopg2==2.5.4
  pyOpenSSL==0.13
  pyasn1==0.1.7
  pycrypto==2.6.1
  pycups==1.9.66
  pycurl==7.19.3
  pygame==1.9.1release
  pygobject==3.12.0
  pyserial==2.6
  pysmbc==1.0.14.1
  python-apt==0.9.3.5ubuntu1
  python-debian==0.1.21-nmu2ubuntu2
  python-openid==2.2.5
  pytz==2014.10
  pyxdg==0.25
  queuelib==1.2.2
  reportlab==3.0
  requests==2.2.1
  roman==2.0.0
  sessioninstaller==0.0.0
  simplegeneric==0.8.1
  six==1.5.2
  software-center-aptd-plugins==0.0.0
  speaklater==1.3
  sqlalchemy-migrate==0.9.2
  sqlparse==0.1.14
  system-service==0.1.6
  tornado==4.0.2
  unity-lens-photos==1.0
  urllib3==1.7.1
  virtualenv==1.11.6
  w3lib==1.10.0
  wsgiref==0.1.2
  wxPython==2.8.12.1
  wxPython-common==2.8.12.1
  xdiagnose==3.6.3build2
  z3c.xmlhttp==0.5.1
  zope.interface==4.0.5
  zope.publisher==4.0.0a4
  zope.traversing==4.0.0
  zope.viewlet==4.0.0a1
  </code></pre>