How do I replace/update the version of the expat library used by Apache?

Question

(Disclaimer: I just started using Linux and don't have much experience with configuring Apache and Python.)

I have a rather common issue that is explained in more depth here http://code.google.com/p/modwsgi/wiki/IssuesWithExpatLibrary. Basically, I'm 99% sure that my main issue is that my Apache is using version 1.95.7 of the expat library, whereas my Python is using version 2.0.1 of the expat library; thus, when I use them together I get a segmentation fault.

As is explained in the link at the very bottom of the page, I need to replace/update the version of the expat library that is used by Apache to the version used by Python. How would I do this? (Keep in mind I'm very inexperienced with this sort of thing.)

EDIT: This issue has been resolved. Below I documented everything I did to install Apache, build Python from source code, install mod_wsgi, and resolve the dreaded expat issue for my reference and for that of anyone else who experiences a similar issue.

1) Installed Ubuntu with Wubi

Installing Apache

2) On Ubuntu, downloaded Apache Unix Source httpd-2.2.21.tar.gz

3) Extracted the source from the Apache HTTPDd tarbell:

gzip -d httpd-2.2.21.tar.gz
tar xvf httpd-2.2.21.tar

4) Configured the Apache HTTPd source tree from within extracted directory:

sudo ./configure --prefix=/usr/local/apache2

5) Built the various parts which form the Apache HTTPd package:

sudo make

6) Installed the package under the directory I specified in step 4

sudo make install

7) Started Apache HTTP Server:

sudo /usr/local/apache2/bin/apachectl -k start

8) Checked localhost and it printed "It works!"

9) Stopped Apache HTTP Server:

sudo /usr/local/apache2/bin/apachectl -k stop

Installing Python from source code

10) Fetched all the common packages needed to build anything (e.g. the compiler etc.)

sudo apt-get install build-essential

11) Edited sources.list file in /etc/apt by adding the exact same "deb" lines contained in the file to the end except with "deb-src":

sudo nano /etc/apt/sources.list

12) Updated apt-get to recognize the change:

sudo apt-get update

13) Fetched all the libraries needed to build Python:

sudo apt-get build-dep python2.7

14) Downloaded python source code Python-2.7.2.tgz, extracted it, and ran the following from within the directory:

sudo ./configure --enable-shared --prefix=/usr/local

15) Built Python:

sudo make

16) Installed Python:

sudo make install

Installing mod_wsgi

17) Downloaded mod_wsgi source code tar ball mod_wsgi-3.3.tar.gz

18) Unpacked and configured with python from within unpacked directory:

sudo ./configure --with-apxs=/usr/local/apache2/bin/apxs \
  --with-python=/usr/local/bin/python2.7

19) Built the configured package:

sudo make

20) Installed in Apache modules:

sudo make install

21) Downloaded Django-1.3.1.tar.gz

22) Extracted file:

tar xzvf Django-1.3.1.tar.gz

23) Installed Django project from within directory:

sudo python setup.py install

24) Edited Apache httpd.conf file:

sudo nano /usr/local/apache2/conf/httpd.conf

Added the following directive to the end of the file:

LoadModule wsgi_module /usr/local/apache2/modules/mod_wsgi.so
WSGIScriptAlias / /usr/local/lib/python2.7/site-packages/django/test.wsgi
<Directory /usr/local/lib/python2.7/site-packages/django>
Order deny,allow
Allow from all
</Directory>

25) Created a test file in django project directory:

sudo nano /usr/local/lib/python2.7/site-packages/django/test.wsgi

Added the following content to the file:

def application(environ, start_response):
    status = '200 OK'
    output = 'Hello World!'
    response_headers = [('Content-type', 'text/plain'),
    ('Content-Length', str(len(output)))]
    start_response(status, response_headers)
    return [output]

26) Started Apache:

sudo /usr/local/apache2/bin/apachectl -k start

27) Tested localhost and it printed "Hello World!"

28) Stopped Apache:

sudo /usr/local/apache2/bin/apachectl -k stop

Testing the Dreaded Expat Issue:

29) Edited test.wsgi file:

sudo nano /usr/local/lib/python2.7/site-packages/django/test.wsgi

Added the following content to the top of the file:

import pyexpat

30) Started Apache:

sudo /usr/local/apache2/bin/apachectl -k start

31) It prints "Hello World!" There is a God.

32) Stopped Apache:

$ sudo /usr/local/apache2/bin/apachectl -k stop

Answer 1

Looking for this? It's pretty well known - I've followed this a couple of times myself.