bug in python infrastructure or in update of pkgsrc/databases/py-mysqldb?

[Klaus Heinz <heinz%NetBSD.org@localhost>]

Hi,

the package databases/py-mysqldb is currently at version 0.9.2 while the
latest source version is at 1.2.2. I needed a later version than is
currently available in pkgsrc, so I tried to update the package.

Unfortunately I am a Python newbie and do not fully understand all
the intricacies of Python, distutils, eggs, setuptools (and pkgsrc on
top of it all :-).

Could someone take a look at the package I came up with?
http://www.NetBSD.org/~heinz/py-mysqldb122.tar.gz

Everything seems to work up to the installation of the package. First,
it produces a single egg file

  MySQL_python-1.2.2-py2.4-netbsd-3.1-i386.egg

in /usr/pkg/lib/python2.4/site-packages/, containing all the files that
should have been installed in the filesystem. 

And second, the installation also changes some .pyc files installed as
part of the required package devel/py-setuptools, eg

  $ ls -alt 
/usr/pkg/lib/python2.4/site-packages/setuptools-0.6c3-py2.4.egg/setuptools/
  drwxr-xr-x  2 root  wheel   1536 May  1 19:06 command/
  -rw-r--r--  1 root  wheel  23777 May  1 19:06 package_index.pyc
  drwxr-xr-x  4 root  wheel   1024 May  1 19:06 ./
  -rw-r--r--  1 root  wheel   5579 May  1 19:06 archive_util.pyc
  -rw-r--r--  1 root  wheel   8660 May  1 19:06 sandbox.pyc
  drwxr-xr-x  4 root  wheel    512 May  1 19:06 ../
  -rw-r--r--  1 root  wheel   6574 May  1 19:06 depends.pyc
  -rw-r--r--  1 root  wheel  28503 May  1 19:06 dist.pyc
  -rw-r--r--  1 root  wheel   1526 May  1 19:06 extension.pyc
  -rw-r--r--  1 root  wheel   3047 May  1 19:06 __init__.pyc
  drwxr-xr-x  2 root  wheel    512 Apr 30 10:46 tests/
  -rw-r--r--  1 root  wheel   2249 Apr 30 00:02 __init__.py
  -rw-r--r--  1 root  wheel   3047 Apr 30 00:02 __init__.pyo
  -rw-r--r--  1 root  wheel   5762 Apr 30 00:02 archive_util.py
  -rw-r--r--  1 root  wheel   5579 Apr 30 00:02 archive_util.pyo
  -rw-r--r--  1 root  wheel   7680 Apr 30 00:02 cli.exe

The first problem I could live with, probably something wrong with my
update to the package.
On the other hand, the second problem of changing already installed
files looks like a serious bug to me. This should not happen(tm).
  
The version of py-setuptools does not matter, 0.6c3 from pkgsrc or the
current version 0.6c5 (as originally required by py-mysqldb 1.2.2) are
both affected.

Is anyone able to help with this?

ciao
     Klaus Heinz