importing site fails - why?

[Helmut Jarausch]

Hi,

as often before, I've cloned a working system (GenToo) onto another 
machine. There, from a livecd and chroot to the cloned root partition

python -v
import site

fails with the following error
Python 2.6.6 (r266:84292, Oct 13 2010, 09:06:24)
[GCC 4.4.4] on linux2
Type "help", "copyright", "credits" or "license" for more information.
dlopen("/usr/lib64/python2.6/lib-dynload/readline.so", 2);
import readline # dynamically loaded from /usr/lib64/python2.6/lib-
dynload/readline.so
>>> import site
# /usr/lib64/python2.6/site.pyc matches /usr/lib64/python2.6/site.py
import site # precompiled from /usr/lib64/python2.6/site.pyc
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/usr/lib64/python2.6/site.py", line 526, in <module>
    main()
  File "/usr/lib64/python2.6/site.py", line 509, in main
    known_paths = addsitepackages(known_paths)
  File "/usr/lib64/python2.6/site.py", line 289, in addsitepackages
    addsitedir(sitedir, known_paths)
  File "/usr/lib64/python2.6/site.py", line 185, in addsitedir
    addpackage(sitedir, name, known_paths)
  File "/usr/lib64/python2.6/site.py", line 159, in addpackage
    if not dircase in known_paths and os.path.exists(dir):
  File "/usr/lib64/python2.6/genericpath.py", line 18, in exists
    st = os.stat(path)
TypeError: stat() argument 1 must be encoded string without NULL bytes, 
not str
>>>​

I'm puzzled and I'd appreciate any hints to the reason for this failure.

Many thanks,
Helmut.