Why does setuptools sometimes remove and then reinstall the same egg?

Question

I am trying to install an egg on a computer where the same egg already exists. Why does he remove the egg and then reinstall it? I call easy_install from a script with parameters:

['-v', '-m', '-f', 'R:/OPTIONS/Stephen/python_eggs', 'mypkg==1.0_r2009_03_12']

When running the easy_install command, this was observed:

Searching for mypkg==1.0-r2009-03-12
Best match: calyon 1.0-r2009-03-12
Processing calyon-1.0_r2009_03_12-py2.4-win32.egg
Removing d:\devtools\python24\lib\site-packages\mypkg-1.0_r2009_03_12-py2.4-win32.egg
Copying mypkg-1.0_r2009_03_12-py2.4-win32.egg to d:\devtools\python24\lib\site-packages

What causes this? Why is the egg removed and reinstalled several times, and in other cases does the egg remain? I have seen this happen several times on my own computer, but I'm not sure how to reproduce the behavior sequentially.

I am using setuptools 0.6c9

Answer 1

, ... .

, mypkg calyon , -r2009-03-12 setuptools ( post release YYYYMMDD), , . , .

, , easy_install easy-install.pth. easy-install.pth ?

http://peak.telecommunity.com/DevCenter/setuptools#specifying-your-project-s-version http://peak.telecommunity.com/DevCenter/setuptools#tagging-and-daily-build-or-snapshot-releases

Answer 2

, .