Python setuptools and STAGEDIR

I'm trying to port a Python network tool called parcel:

My work-in-progress port is available here:

The problem is that the python byte-compiler is embedding STAGEDIR in the output:

<<<ROOT@manatee.acadix>>> /usr/wip/ftp/py-parcel-devel 549 # strings work/stage/usr/local/lib/python2.7/site-packages/parcel-0.1.13-py2.7.egg/parcel/version.pyc|grep site-package

I've ported many other python packages before and never ran into this. Here's an example of what I normally see:

<<<ROOT@manatee.acadix>>> /usr/wip/biology/py-pyqi 509 # strings ./work/stage/usr/local/lib/python2.7/site-packages/pyqi/util.pyc|grep site-package

I've been digging and examining the source code, but so far have come up empty. If you're familiar with python setuptools and how they interact with destdir support, I'd appreciate a pointer or two.