Don't forget version at the end of setup.py, write it only if changed. This fixes issue159: "python setup.py install" shouldn't write new files in the working dir if one has done "python setup.py build" first.

#!/bin/sh
hg init
echo This is file a1 > a
hg add a
hg commit -m "commit #0" -d "1000000 0"
ls
echo This is file b1 > b
hg add b
hg commit -m "commit #1" -d "1000000 0"
hg co 0
# B should disappear
ls