virtualenv --system-site-packages not using system site packages
python, virtualenv
Solution
I'm not sure what went wrong when you created the `virtualenv` but clearly it does not have the expected values in its `sys.path`. If you use `virtualenv x --system-site-packages` to create virtual environment `x`, you should see the parent Python's `site-packages` directory on `sys.path`. In your listing above, the last item for the inside venv case should be the same as the normal case: `/app/python/lib/python2.7/site-packages`. You might try experimenting creating two simple `virtualenv`, with and without `--system-site-packages`, to see if that is the case. If not, you might try simplifying your configuration and trying again, like removing environment variables like `PYTHONPATH` which you should not need to set.
Problem
I am under the impression that using the --system-site-packages flag with virtualenv will allow the virtual environment to use the already installed system packages. However I am finding that this is not the case. I am using a custom compiled version of python. You can see the problem in the steps below. ``` [user@machine django]$ which python /app/python/bin/python [user@machine django]$ which pip /app/python/bin/pip [user@machine django]$ which virtualenv /app/python/bin/virtualenv [user@machine django]$ python Python 2.7.3 (default, Jul 27 2012, 11:30:41) [GCC 4.1.2 20080704 (Red Hat 4.1.2-50)] on linux2 Type "help", "copyright", "credits" or "license" for more information. >>> import django >>> exit() [user@machine django]$ pip freeze Django==1.4.2 distribute==0.6.30 mercurial==2.3.2 python-ldap==2.4.10 virtualenv==1.8.2 wsgiref==0.1.2 [user@machine django]$ pip --version pip 1.2.1 from /app/python/lib/python2.7/site-packages (python 2.7) [user@machine django]$ env <snip> LD_LIBRARY_PATH=/app/python/lib:/app/openldap/lib:/app/instantclient_11_2 PATH=/app/python/bin:/app/openldap/bin:/usr/kerberos/bin:/usr/local/bin:/bin:/usr/bin:/usr/local/bin/cfdelivered:/home/user/bin:/app/oracle/product/java/jdk1.6.0_30/bin PYTHONPATH=/app/python/lib/python2.7 [user@machine django]$ virtualenv --system-site-packages --distribute --python /app/python/bin/python2.7 foo Running virtualenv with interpreter /app/python/bin/python2.7 New python executable in foo/bin/python2.7 Also creating executable in foo/bin/python Installing distribute...<snip>...done. Installing pip................done. [user@machine django]$ . foo/bin/activate (foo)[user@machine django]$ which python /app/xxx/django/foo/bin/python (foo)[user@machine django]$ which pip /app/xxx/django/foo/bin/pip (foo)[user@machine django]$ env <snip> LD_LIBRARY_PATH=/app/python/lib:/app/openldap/lib:/app/instantclient_11_2 VIRTUAL_ENV=/app/xxx/django/foo PATH=/app/xxx/django/foo/bin:/app/python/bin:/app/openldap/bin:/usr/kerberos/bin:/usr/local/bin:/bin:/usr/bin:/usr/local/bin/cfdelivered:/home/user/bin:/app/oracle/product/java/jdk1.6.0_30/bin PYTHONPATH=/app/python/lib/python2.7 (foo)[user@machine django]$ python Python 2.7.3 (default, Jul 27 2012, 11:30:41) [GCC 4.1.2 20080704 (Red Hat 4.1.2-50)] on linux2 Type "help", "copyright", "credits" or "license" for more information. >>> import django Traceback (most recent call last): File "<stdin>", line 1, in <module> ImportError: No module named django >>> ``` Results of python2.7 -c "import sys;print(sys.path)" Normal: ``` [user@machine django]$ python2.7 -c "import sys;print(sys.path)" ['', '/app/python/lib/python2.7/site-packages/cx_Oracle-5.1.2-py2.7-linux-x86_64.egg', '/app/python/lib/python2.7/site-packages/python_ldap-2.4.10-py2.7-linux-x86_64.egg', '/app/python/lib/python2.7', '/app/python/lib/python27.zip', '/app/python/lib/python2.7/plat-linux2', '/app/python/lib/python2.7/lib-tk', '/app/python/lib/python2.7/lib-old', '/app/python/lib/python2.7/lib-dynload', '/app/python/lib/python2.7/site-packages'] ``` Inside venv: ``` (foo)[user@machine django]$ python2.7 -c "import sys;print(sys.path)" ['', '/app/xxx/django/foo/lib/python2.7/site-packages/distribute-0.6.28-py2.7.egg', '/app/xxx/django/foo/lib/python2.7/site-packages/pip-1.2.1-py2.7.egg', '/app/python/lib/python2.7', '/app/xxx/django/foo/lib/python27.zip', '/app/xxx/django/foo/lib/python2.7', '/app/xxx/django/foo/lib/python2.7/plat-linux2', '/app/xxx/django/foo/lib/python2.7/lib-tk', '/app/xxx/django/foo/lib/python2.7/lib-old', '/app/xxx/django/foo/lib/python2.7/lib-dynload', '/app/xxx/django/foo/lib/python2.7/site-packages'] ```