Why #egg=foo when pip-installing from git repo

Question

When I do a "pip install -e ..." to install from a git repo, I have to specify #egg=somename or pip complains. For example:

pip install -e git://github.com/hiidef/oauth2app.git#egg=oauth2app 

What's the significance of this "egg" string?

Answer 1

per pip install -h the "egg" string is the directory that gets checked out as part of the install