title: Prompting user on package install "pip install <pkg>"
body: <p>I've created a tar.gz of a package that includes a setup.py file. setup.py uses the setup() function provided in distutils.core. I want to prompt the user when they run "pip install .tar.gz". Unfortunately, it looks like pip redirects all stdout and stderr of the "python setup.py install" command through a special log filter, which reads stdout line by line. This means I can't have a prompt such as "Email: ..." since "Email: " will not get printed until after the user has pressed enter. Also, the log filter indents every line of output, which is not ideal.</p>