UserWarning: Module _mysql was already imported from /usr/lib/pymodules/python2.6/_mysql.so

Question

I have deployed a django project on a server running under debian lenny. Every time it starts up the following warning pops up:

/var/www/environment/XXX/src/django-pytest/django_pytest/test_runner.py:3: UserWarning: Module _mysql was already imported from /usr/lib/pymodules/python2.6/_mysql.so, but /usr/lib/pymodules/python2.6 is being added to sys.path
  from pkg_resources import load_entry_point

There is more than one Django project on that particular server, each running inside their own virtualenv (with Python packages installed via pip). However, they also access the system-wide site-packages (which are installed via apt-get install).

This particular project has the following Python packages:

$ /var/www/environment/XXX/bin/pip freeze --local
Django==1.2.4
Fabric==0.9.4
South==0.7.3
distribute==0.6.10
django-pagination==1.0.7
-e git+http://github.com/galileo-press/django-pytest.git@7c1fa0180ca16c129850de3c3d912cd369fba687#egg=django_pytest-0.1.4-py2.6-dev
django-sorting==0.1
django-templatetag-sugar==0.1
paramiko==1.7.6
py==1.4.3
pycrypto==2.3
pytest==2.0.0

Under debian python-mysqldb 1.2.2-10+b1 is installed and the files live in

$ apt-file list python-mysqldb
python-mysqldb: /usr/lib/pyshared/python2.5/_mysql.so
python-mysqldb: /usr/lib/pyshared/python2.6/_mysql.so
python-mysqldb: /usr/share/pyshared/MySQL_python-1.2.2.egg-info/PKG-INFO
python-mysqldb: /usr/share/pyshared/MySQL_python-1.2.2.egg-info/SOURCES.txt
python-mysqldb: /usr/share/pyshared/MySQL_python-1.2.2.egg-info/dependency_links.txt
python-mysqldb: /usr/share/pyshared/MySQL_python-1.2.2.egg-info/top_level.txt
python-mysqldb: /usr/share/pyshared/MySQLdb/__init__.py
...

Although this is only a minor annoyance, I really like to fix this.

Can anyone help?

Update: Here's the output from yolk:

Cheetah         - 2.4.2.1      - active development (/usr/lib/pymodules/python2.6)
Django          - 1.2.3        - non-active development (/usr/lib/pymodules/python2.6)
Django          - 1.2.4        - active 
Fabric          - 0.9.4        - active 
Jinja2          - 2.5.5        - active development (/usr/lib/pymodules/python2.6)
Logbook         - 0.3          - active development (/usr/local/lib/python2.6/dist-packages/Logbook-0.3-py2.6-linux-x86_64.egg)
MarkupSafe      - 0.9.2        - active development (/usr/lib/python2.6/dist-packages)
MySQL-python    - 1.2.2        - active development (/usr/lib/pymodules/python2.6)
PIL             - 1.1.7        - active development (/usr/lib/python2.6/dist-packages/PIL)
Python          - 2.6.6        - active development (/usr/lib/python2.6/lib-dynload)
South           - 0.7.3        - active 
boto            - 1.9b         - active development (/usr/lib/pymodules/python2.6)
distribute      - 0.6.10       - active 
distribute      - 0.6.14       - non-active development (/usr/lib/python2.6/dist-packages)
django-pagination - 1.0.7        - active 
django-pytest   - 0.1.4        - active development (/var/www/environment/XXX/src/django-pytest)
django-sorting  - 0.1          - active 
django-templatetag-sugar - 0.1          - active 
flup            - 1.0.2        - active development (/usr/lib/pymodules/python2.6)
lxml            - 2.2.8        - active development (/usr/lib/python2.6/dist-packages)
mercurial       - 1.6.4        - active development (/usr/lib/pymodules/python2.6)
paramiko        - 1.7.6        - active 
pip             - 0.7.2        - active 
psycopg2        - 2.2.1        - active development (/usr/lib/python2.6/dist-packages)
py              - 1.3.3        - non-active development (/usr/lib/pymodules/python2.6)
py              - 1.4.1        - non-active 
py              - 1.4.3        - active 
pycrypto        - 2.3          - active 
pytest          - 2.0.0        - active 
python-amazon-product-api - 0.2.5a1      - active development (/var/www/environment/XXX/src/amazonproduct)
python-amazon-product-api - 0.2.5a1      - active development (/var/www/environment/XXX/src/amazonproduct)
python-amazon-product-api - 0.2.5a1      - non-active development (/usr/local/lib/python2.6/dist-packages/python_amazon_product_api-0.2.5a1-py2.6.egg)
python-amazon-product-api - 0.2.5a1      - non-active development (/usr/local/lib/python2.6/dist-packages/python_amazon_product_api-0.2.5a1-py2.6.egg)
python-dateutil - 1.4.1        - active development (/usr/lib/pymodules/python2.6)
setuptools      - 0.6c11       - active development (/usr/lib/python2.6/dist-packages)
stdeb           - 0.6.0        - active development (/usr/lib/pymodules/python2.6)
virtualenv      - 1.4.9        - active development (/usr/lib/pymodules/python2.6)
web.py          - 0.34         - active development (/usr/lib/pymodules/python2.6)
wsgiref         - 0.1.2        - active development (/usr/lib/python2.6)
yolk            - 0.4.1        - active 

Update 2: My sys.paths are:

/var/www/environment/XXX/bin/python -c "import sys; print '\n'.join(sys.path)"

/var/www/environment/XXX/lib/python2.6/site-packages/distribute-0.6.10-py2.6.egg
/var/www/environment/XXX/lib/python2.6/site-packages/pip-0.7.2-py2.6.egg
/var/www/environment/XXX/src/django-pytest
/var/www/environment/XXX/src/amazonproduct
/var/www/environment/XXX/lib/python2.6
/var/www/environment/XXX/lib/python2.6/plat-linux2
/var/www/environment/XXX/lib/python2.6/lib-tk
/var/www/environment/XXX/lib/python2.6/lib-old
/var/www/environment/XXX/lib/python2.6/lib-dynload
/usr/lib/python2.6
/usr/lib64/python2.6
/usr/lib/python2.6/plat-linux2
/usr/lib/python2.6/lib-tk
/usr/lib64/python2.6/lib-tk
/var/www/environment/XXX/lib/python2.6/site-packages
/usr/local/lib/python2.6/dist-packages/Logbook-0.3-py2.6-linux-x86_64.egg
/usr/lib/python2.6/dist-packages/PIL
/usr/local/lib/python2.6/dist-packages/python_amazon_product_api-0.2.5a1-py2.6.egg
/usr/lib/pymodules/python2.6
/usr/local/lib/python2.6/site-packages
/usr/local/lib/python2.6/dist-packages
/usr/lib/python2.6/dist-packages

When doing the same with python manage.py shell I get the same list with the exception of

/usr/lib64/python2.6

missing.

Answer 1

Your problem was caused by having 2 "distribute" packages installed as can be seen from the yolk output provided.

Answer 2

I have simply removed django_pytest from INSTALLED_APPS. The problem is now gone. Not nice but it works (tm).