Where does virtualenv get its version of site.py from?

[Napoleon-BlownApart]

[Ubuntu 14.04]
I have Python 2.7.6 and Python 3.4.3 installed on my system.
I'm in the process of learning how virtual environments are managed and have come across an anomaly I can't explain.
When I create a new environment mkvirtualenv myenv (regardless of the site-packages flag), I end up with a site.py that is different from the Python versions I have on my system. I've searched my server for a template file which virtualenv copies into my environment, but there aren't any. Where does this version come from?

I have read #228 but that hasn't help me understand.

[gaborbernat]

It's a custom site.py baked within virtualenv code itself.

[gaborbernat]

https://github.com/pypa/virtualenv/blob/master/virtualenv_embedded/site.py

[Ivoz]

Specifically it was last cribbed from Python 2.6.

[gaborbernat]

That's not true, we've been syncing it up from time to time.