title: installing a Python package source tarball with pip
body: <p>I'm trying to figure out how to construct a Python source package that is installable via pip. I tried creating a test project with the setup.py file described on <a href="http://packages.python.org/an_example_pypi_project/setuptools.html" rel="noreferrer">http://packages.python.org/an_example_pypi_project/setuptools.html</a>
  and a number of simple test files in the specified directories.</p>
  
  <p>After creating a source tarball for the project named <code>dist/an_example_pypi_project-0.0.4.tar.gz</code> with <code>python setup.py sdist</code>, I tried installing it in a virtualenv environment called <code>~/TEST</code> with 
  <code>~/TEST/bin/pip install dist/an_example_pypi_project-0.0.4.tar.gz</code>. Although pip didn't throw any error, it didn't seem to install the package:</p>
  
  <pre class="lang-none prettyprint-override"><code>$ ~/TEST/bin/pip install dist/an_example_pypi_project-0.0.4.tar.gz 
  Unpacking ./dist/an_example_pypi_project-0.0.4.tar.gz
    Running setup.py egg_info for package from file:///home/lebedov/an_example_pypi_project/dist/an_example_pypi_project-0.0.4.tar.gz
  
  Cleaning up...
  $ find ~/TEST -name "an_example*"
  $
  </code></pre>
  
  <p>Note that I was able to install from the tarball using easy_install:</p>
  
  <pre class="lang-none prettyprint-override"><code>$ ~/TEST/bin/easy_install dist/an_example_pypi_project-0.0.4.tar.gz 
  Processing an_example_pypi_project-0.0.4.tar.gz
  Running an_example_pypi_project-0.0.4/setup.py -q bdist_egg --dist-dir /tmp/easy_install-tfXxeW/an_example_pypi_project-0.0.4/egg-dist-tmp-N2QY_N
  warning: build_py: byte-compiling is disabled, skipping.
  
  warning: install_lib: byte-compiling is disabled, skipping.
  
  zip_safe flag not set; analyzing archive contents...
  Adding an-example-pypi-project 0.0.4 to easy-install.pth file
  
  Installed /home/lebedov/TEST/lib/python2.7/site-packages/an_example_pypi_project-0.0.4-py2.7.egg
  Processing dependencies for an-example-pypi-project==0.0.4
  Finished processing dependencies for an-example-pypi-project==0.0.4
  $ find ~/TEST/ -name "an_example*"                                  
  /home/lebedov/TEST/lib/python2.7/site-packages/an_example_pypi_project-0.0.4-py2.7.egg
  </code></pre>
  
  <p>Am I neglecting to configure something in the package in order to make it installable with pip? I'm using Python 2.7.2, distribute 0.6.21, virtualenv 1.7, and pip 1.0.2.</p>