Bug Tracker

Changes between Version 1 and Version 2 of TracModPython


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Timestamp:
Nov 29, 2015, 3:01:08 AM (6 years ago)
Author:
trac
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  • TracModPython

    v1 v2  
    1 = Trac and mod_python =
    21[[TracGuideToc]]
    32
     3= Trac and mod_python
     4
     5Mod_python is an [https://httpd.apache.org/ Apache] module that embeds the Python interpreter within the server, so that web-based applications in Python will run many times faster than traditional CGI and will have the ability to retain database connections.
    46Trac supports [http://www.modpython.org/ mod_python], which speeds up Trac's response times considerably, especially compared to [TracCgi CGI], and permits use of many Apache features not possible with [wiki:TracStandalone tracd]/mod_proxy.
    57
    6 These instructions are for Apache 2; if you are still using Apache 1.3, you may have some luck with [trac:wiki:TracModPython2.7 TracModPython2.7].
    7 
    8 == Simple configuration ==
     8These instructions are for Apache 2. If you are using Apache 1.3, you may have some luck with [trac:wiki:TracModPython2.7 TracModPython2.7], but that is a deprecated setup.
     9
     10[[PageOutline(2-3,Overview,inline)]]
     11
     12== Simple configuration: single project == #Simpleconfiguration
    913
    1014If you just installed mod_python, you may have to add a line to load the module in the Apache configuration:
    11 {{{
     15{{{#!apache
    1216LoadModule python_module modules/mod_python.so
    1317}}}
    1418
    15 ''Note: The exact path to the module depends on how the HTTPD installation is laid out.''
    16 
    17 On Debian using apt-get
    18 {{{
     19'''Note''': The exact path to the module depends on how the HTTPD installation is laid out.
     20
     21On Debian using apt-get:
     22{{{#!sh
    1923apt-get install libapache2-mod-python libapache2-mod-python-doc
    2024}}}
    21 (Still on Debian) after you have installed mod_python, you must enable the modules in apache2 (equivalent of the above Load Module directive):
    22 {{{
    23 a2enmod mod_python
    24 }}}
     25
     26Still on Debian, after you have installed mod_python, you must enable the modules in apache2, equivalent to the above Load Module directive:
     27{{{#!sh
     28a2enmod python
     29}}}
     30
    2531On Fedora use, using yum:
    26 {{{
     32{{{#!sh
    2733yum install mod_python
    2834}}}
    29 You can test your mod_python installation by adding the following to your httpd.conf.  You should remove this when you are done testing for security reasons. Note: mod_python.testhandler is only available in mod_python 3.2+.
    30 {{{
    31 #!xml
     35
     36You can test your mod_python installation by adding the following to your httpd.conf. You should remove this when you are done testing for security reasons. Note: mod_python.testhandler is only available in mod_python 3.2+.
     37{{{#!apache
    3238<Location /mpinfo>
    3339   SetHandler mod_python
    3440   PythonInterpreter main_interpreter
    3541   PythonHandler mod_python.testhandler
     42   Order allow,deny
     43   Allow from all
    3644</Location>
    3745}}}
    3846
    3947A simple setup of Trac on mod_python looks like this:
    40 {{{
    41 #!xml
     48{{{#!apache
    4249<Location /projects/myproject>
    4350   SetHandler mod_python
     
    4653   PythonOption TracEnv /var/trac/myproject
    4754   PythonOption TracUriRoot /projects/myproject
    48 </Location>
    49 }}}
    50 
    51 The option '''`TracUriRoot`''' may or may not be necessary in your setup. Try your configuration without it; if the URLs produced by Trac look wrong, if Trac does not seem to recognize URLs correctly, or you get an odd "No handler matched request to..." error, add the '''`TracUriRoot`''' option.  You will notice that the `Location` and '''`TracUriRoot`''' have the same path.
    52 
    53 The options available are
    54 {{{
    55     # For a single project
    56     PythonOption TracEnv /var/trac/myproject
    57     # For multiple projects
    58     PythonOption TracEnvParentDir /var/trac/myprojects
    59     # For the index of multiple projects
    60     PythonOption TracEnvIndexTemplate /srv/www/htdocs/trac/project_list_template.html
    61     # A space delimitted list, with a "," between key and value pairs.
    62     PythonOption TracTemplateVars key1,val1 key2,val2
    63     # Useful to get the date in the wanted order
    64     PythonOption TracLocale en_GB.UTF8
    65     # See description above       
    66     PythonOption TracUriRoot /projects/myproject
    67 }}}
    68 
    69 === Python Egg Cache ===
    70 
    71 Compressed python eggs like Genshi are normally extracted into a directory named `.python-eggs` in the users home directory. Since apache's home usually is not writable an alternate egg cache directory can be specified like this:
    72 {{{
     55   Order allow,deny
     56   Allow from all
     57</Location>
     58}}}
     59
     60The option '''`TracUriRoot`''' may or may not be necessary in your setup. Try your configuration without it; if the URLs produced by Trac look wrong, if Trac does not seem to recognize URLs correctly, or you get an odd "No handler matched request to..." error, add the '''`TracUriRoot`''' option. You will notice that the `Location` and '''`TracUriRoot`''' have the same path.
     61
     62The options available are:
     63{{{#!apache
     64# For a single project
     65PythonOption TracEnv /var/trac/myproject
     66
     67# For multiple projects
     68PythonOption TracEnvParentDir /var/trac/myprojects
     69
     70# For the index of multiple projects
     71PythonOption TracEnvIndexTemplate /srv/www/htdocs/trac/project_list_template.html
     72
     73# A space delimitted list, with a "," between key and value pairs.
     74PythonOption TracTemplateVars key1,val1 key2,val2
     75
     76# Useful to get the date in the wanted order
     77PythonOption TracLocale en_GB.UTF8
     78
     79# See description above       
     80PythonOption TracUriRoot /projects/myproject
     81}}}
     82
     83=== Python Egg Cache
     84
     85Compressed Python eggs like Genshi are normally extracted into a directory named `.python-eggs` in the users home directory. Since Apache's home usually is not writeable, an alternate egg cache directory can be specified like this:
     86{{{#!apache
    7387PythonOption PYTHON_EGG_CACHE /var/trac/myprojects/egg-cache
    7488}}}
    7589
    76 or you can uncompress the Genshi egg to resolve problems extracting from it.
    77 === Configuring Authentication ===
    78 
    79 Creating password files and configuring authentication works similar to the process for [wiki:TracCgi#AddingAuthentication CGI]:
    80 {{{
    81 #!xml
    82 <Location /projects/myproject/login>
    83   AuthType Basic
    84   AuthName "myproject"
    85   AuthUserFile /var/trac/myproject/.htpasswd
    86   Require valid-user
    87 </Location>
    88 }}}
    89 
    90 Configuration for mod_ldap authentication in Apache is a bit tricky (httpd 2.2.x and OpenLDAP: slapd 2.3.19)
    91 
    92 1. You need to load the following modules in Apache httpd.conf
    93 {{{
    94 LoadModule ldap_module modules/mod_ldap.so
    95 LoadModule authnz_ldap_module modules/mod_authnz_ldap.so
    96 }}}
    97 
    98 2. Your httpd.conf also needs to look something like:
    99 
    100 {{{
    101 #!xml
    102 <Location /trac/>
    103   SetHandler mod_python
    104   PythonInterpreter main_interpreter
    105   PythonHandler trac.web.modpython_frontend
    106   PythonOption TracEnv /home/trac/
    107   PythonOption TracUriRoot /trac/
    108   Order deny,allow
    109   Deny from all
    110   Allow from 192.168.11.0/24
    111   AuthType Basic
    112   AuthName "Trac"
    113   AuthBasicProvider "ldap"
    114   AuthLDAPURL "ldap://127.0.0.1/dc=example,dc=co,dc=ke?uid?sub?(objectClass=inetOrgPerson)"
    115   authzldapauthoritative Off
    116   require valid-user
    117 </Location>
    118 }}}
    119 
    120 Or the LDAP interface to a Microsoft Active Directory:
    121 
    122 {{{
    123 #!xml
    124 <Location /trac/>
    125   SetHandler mod_python
    126   PythonInterpreter main_interpreter
    127   PythonHandler trac.web.modpython_frontend
    128   PythonOption TracEnv /home/trac/
    129   PythonOption TracUriRoot /trac/
    130   Order deny,allow
    131   Deny from all
    132   Allow from 192.168.11.0/24
    133   AuthType Basic
    134   AuthName "Trac"
    135   AuthBasicProvider "ldap"
    136   AuthLDAPURL "ldap://adserver.company.com:3268/DC=company,DC=com?sAMAccountName?sub?(objectClass=user)"
    137   AuthLDAPBindDN       [email protected]
    138   AuthLDAPBindPassword "the_password"
    139   authzldapauthoritative Off
    140   # require valid-user
    141   require ldap-group CN=Trac Users,CN=Users,DC=company,DC=com
    142 </Location>
    143 }}}
    144 
    145 Note 1: This is the case where the LDAP search will get around the multiple OUs, conecting to Global Catalog Server portion of AD (Notice the port is 3268, not the normal LDAP 389). The GCS is basically a "flattened" tree which allows searching for a user without knowing to which OU they belong.
    146 
    147 Note 2: Active Directory requires an authenticating user/password to access records (AuthLDAPBindDN and AuthLDAPBindPassword).
    148 
    149 Note 3: The directive "require ldap-group ..."  specifies an AD group whose members are allowed access.
    150 
    151 
    152 === Setting the Python Egg Cache ===
    153 
    154 If the Egg Cache isn't writeable by your Web server, you'll either have to change the permissions, or point Python to a location where Apache can write. This can manifest itself as a ''500 internal server error'' and/or a complaint in the syslog.
    155 
    156 {{{
    157 #!xml
     90Or you can uncompress the Genshi egg to resolve problems extracting from it.
     91
     92=== Configuring Authentication
     93
     94See corresponding section in the [wiki:TracModWSGI#ConfiguringAuthentication] page.
     95
     96== Advanced Configuration
     97
     98=== Setting the Python Egg Cache
     99
     100If the Egg Cache isn't writeable by your Web server, you'll either have to change the permissions, or point Python to a location where Apache can write. This can manifest itself as a `500 internal server error` and/or a complaint in the syslog.
     101
     102{{{#!apache
    158103<Location /projects/myproject>
    159104  ...
     
    163108}}}
    164109
    165 
    166 === Setting the !PythonPath ===
    167 
    168 If the Trac installation isn't installed in your Python path, you'll have to tell Apache where to find the Trac mod_python handler  using the `PythonPath` directive:
    169 {{{
    170 #!xml
     110=== Setting the !PythonPath
     111
     112If the Trac installation isn't installed in your Python path, you will have to tell Apache where to find the Trac mod_python handler  using the `PythonPath` directive:
     113{{{#!apache
    171114<Location /projects/myproject>
    172115  ...
     
    178121Be careful about using the !PythonPath directive, and ''not'' `SetEnv PYTHONPATH`, as the latter won't work.
    179122
    180 == Setting up multiple projects ==
     123=== Setting up multiple projects
    181124
    182125The Trac mod_python handler supports a configuration option similar to Subversion's `SvnParentPath`, called `TracEnvParentDir`:
    183 {{{
    184 #!xml
     126{{{#!apache
    185127<Location /projects>
    186128  SetHandler mod_python
     
    195137
    196138If you don't want to have the subdirectory listing as your projects home page you can use a
    197 {{{
    198 #!xml
     139{{{#!apache
    199140<LocationMatch "/.+/">
    200141}}}
     
    203144
    204145You can also use the same authentication realm for all of the projects using a `<LocationMatch>` directive:
    205 {{{
    206 #!xml
     146{{{#!apache
    207147<LocationMatch "/projects/[^/]+/login">
    208148  AuthType Basic
     
    213153}}}
    214154
    215 == Virtual Host Configuration ==
    216 
    217 Below is the sample configuration required to set up your trac as a virtual server (i.e. when you access it at the URLs like
    218 !http://trac.mycompany.com):
    219 
    220 {{{
    221 #!xml
    222 <VirtualHost * >
     155=== Virtual Host Configuration
     156
     157Below is the sample configuration required to set up your Trac as a virtual server, ie when you access it at the URLs like
     158`http://trac.mycompany.com`:
     159
     160{{{#!apache
     161<VirtualHost *>
    223162    DocumentRoot /var/www/myproject
    224163    ServerName trac.mycompany.com
     
    240179
    241180This does not seem to work in all cases. What you can do if it does not:
    242  * Try using `<LocationMatch>` instead of `<Location>`
    243  * <Location /> may, in your server setup, refer to the complete host instead of simple the root of the server. This means that everything (including the login directory referenced below) will be sent to python and authentication does not work (i.e. you get the infamous Authentication information missing error). If this applies to you, try using a sub-directory for trac instead of the root (i.e. /web/ and /web/login instead of / and /login).
     181 * Try using `<LocationMatch>` instead of `<Location>`.
     182 * `<Location />` may, in your server setup, refer to the complete host instead of simple the root of the server. This means that everything (including the login directory referenced below) will be sent to Python and authentication does not work, ie you get the infamous Authentication information missing error. If this is the case, try using a sub-directory for Trac instead of the root, ie /web/ and /web/login instead of / and /login.
    244183 * Depending on apache's `NameVirtualHost` configuration, you may need to use `<VirtualHost *:80>` instead of `<VirtualHost *>`.
    245184
    246 For a virtual host that supports multiple projects replace "`TracEnv`" /var/trac/myproject with "`TracEnvParentDir`" /var/trac/
    247 
    248 Note: !DocumentRoot should not point to your Trac project env. As Asmodai wrote on #trac: "suppose there's a webserver bug that allows disclosure of !DocumentRoot they could then leech the entire Trac environment".
    249 
    250 == Troubleshooting ==
    251 
    252 In general, if you get server error pages, you can either check the Apache error log, or enable the `PythonDebug` option:
    253 {{{
    254 #!xml
     185For a virtual host that supports multiple projects replace `TracEnv /var/trac/myproject` with `TracEnvParentDir /var/trac`.
     186
     187'''Note''': !DocumentRoot should not point to your Trac project env. As Asmodai wrote on #trac: "suppose there's a webserver bug that allows disclosure of !DocumentRoot they could then leech the entire Trac environment".
     188
     189== Troubleshooting
     190
     191If you get server error pages, you can either check the Apache error log, or enable the `PythonDebug` option:
     192{{{#!apache
    255193<Location /projects/myproject>
    256194  ...
     
    261199For multiple projects, try restarting the server as well.
    262200
     201=== Login Not Working
     202
     203If you've used `<Location />` directive, it will override any other directives, as well as `<Location /login>`.
     204The workaround is to use negation expression as follows (for multi project setups):
     205{{{#!apache
     206#this one for other pages
     207<Location ~ "/*(?!login)">
     208   SetHandler mod_python
     209   PythonHandler trac.web.modpython_frontend
     210   PythonOption TracEnvParentDir /projects
     211   PythonOption TracUriRoot /
     212</Location>
     213
     214#this one for login page
     215<Location ~ "/[^/]+/login">
     216   SetHandler mod_python
     217   PythonHandler trac.web.modpython_frontend
     218   PythonOption TracEnvParentDir /projects
     219   PythonOption TracUriRoot /
     220
     221   #remove these if you don't want to force SSL
     222   RewriteEngine On
     223   RewriteCond %{HTTPS} off
     224   RewriteRule (.*) https://%{HTTP_HOST}%{REQUEST_URI}
     225
     226   AuthType Basic
     227   AuthName "Trac"
     228   AuthUserFile /projects/.htpasswd
     229   Require valid-user
     230</Location>
     231}}}
     232
    263233=== Expat-related segmentation faults === #expat
    264234
    265235This problem will most certainly hit you on Unix when using Python 2.4.
    266 In Python 2.4, some version of Expat (an XML parser library written in C) is used,
    267 and if Apache is using another version, this results in segmentation faults.
    268 As Trac 0.11 is using Genshi, which will indirectly use Expat, that problem
    269 can now hit you even if everything was working fine before with Trac 0.10.
    270 
    271 See Graham Dumpleton's detailed [http://www.dscpl.com.au/wiki/ModPython/Articles/ExpatCausingApacheCrash explanation and workarounds] for the issue.
    272 
    273 === Form submission problems ===
     236In Python 2.4, some version of [http://expat.sourceforge.net/ Expat] (an XML parser library written in C) is used and if Apache is using another version, this results in segmentation faults.
     237As Trac 0.11 is using Genshi, which will indirectly use Expat, that problem can now hit you even if everything was working fine before with Trac 0.10. This problem has not been reported for Python 2.5+, so best to upgrade.
     238
     239=== Form submission problems
    274240
    275241If you're experiencing problems submitting some of the forms in Trac (a common problem is that you get redirected to the start page after submission), check whether your {{{DocumentRoot}}} contains a folder or file with the same path that you mapped the mod_python handler to. For some reason, mod_python gets confused when it is mapped to a location that also matches a static resource.
    276242
    277 === Problem with virtual host configuration ===
    278 
    279 If the <Location /> directive is used, setting the `DocumentRoot` may result in a ''403 (Forbidden)'' error. Either remove the `DocumentRoot` directive, or make sure that accessing the directory it points is allowed (in a corresponding `<Directory>` block).
    280 
    281 Using <Location /> together with `SetHandler` resulted in having everything handled by mod_python, which leads to not being able download any CSS or images/icons. I used <Location /trac> `SetHandler None` </Location> to circumvent the problem, though I do not know if this is the most elegant solution.
    282 
    283 === Problem with zipped egg ===
    284 
    285 It's possible that your version of mod_python will not import modules from zipped eggs. If you encounter an `ImportError: No module named trac` in your Apache logs but you think everything is where it should be, this might be your problem. Look in your site-packages directory; if the Trac module appears as a ''file'' rather than a ''directory'', then this might be your problem. To rectify, try installing Trac using the `--always-unzip` option, like this:
    286 
    287 {{{
     243=== Problem with virtual host configuration
     244
     245If the <Location /> directive is used, setting the `DocumentRoot` may result in a ''403 (Forbidden)'' error. Either remove the `DocumentRoot` directive, or make sure that accessing the directory it points is allowed, in a corresponding `<Directory>` block.
     246
     247Using <Location /> together with `SetHandler` resulted in having everything handled by mod_python, which leads to not being able to download any CSS or images/icons. Use <Location /trac> `SetHandler None` </Location> to circumvent the problem, though this may not be the most elegant solution.
     248
     249=== Problem with zipped egg
     250
     251It's possible that your version of mod_python will not import modules from zipped eggs. If you encounter an `ImportError: No module named trac` in your Apache logs but you think everything is where it should be, this might be your problem. Look in your site-packages directory; if the Trac module appears as a ''file'' rather than a ''directory'', then this might be your problem. To rectify this, try installing Trac using the `--always-unzip` option:
     252
     253{{{#!sh
    288254easy_install --always-unzip Trac-0.12b1.zip
    289255}}}
    290256
    291 === Using .htaccess ===
     257=== Using .htaccess
    292258
    293259Although it may seem trivial to rewrite the above configuration as a directory in your document root with a `.htaccess` file, this does not work. Apache will append a "/" to any Trac URLs, which interferes with its correct operation.
    294260
    295 It may be possible to work around this with mod_rewrite, but I failed to get this working. In all, it is more hassle than it is worth. Stick to the provided instructions. :)
    296 
    297 A success story: For me it worked out-of-box, with following trivial config:
    298 {{{
     261It may be possible to work around this with mod_rewrite, but I failed to get this working. In all, it is more hassle than it is worth.
     262
     263This also works out-of-box, with following trivial config:
     264{{{#!apache
    299265SetHandler mod_python
    300266PythonInterpreter main_interpreter
     
    309275}}}
    310276
    311 The `TracUriRoot` is obviously the path you need to enter to the browser to get to the trac (e.g. domain.tld/projects/trac)
    312 
    313 === Additional .htaccess help ===
    314 
    315 If you are using the .htaccess method you may have additional problems if your trac directory is inheriting .htaccess directives from another. This may also help to add to your .htaccess file:
    316 
    317 {{{
     277The `TracUriRoot` is obviously the path you need to enter to the browser to get to Trac, eg `domain.tld/projects/trac`.
     278
     279=== Additional .htaccess help
     280
     281If you are using the .htaccess method you may have additional problems if your Trac directory is inheriting .htaccess directives from another. This may also help to add to your .htaccess file:
     282
     283{{{#!apache
    318284<IfModule mod_rewrite.c>
    319285  RewriteEngine Off
     
    321287}}}
    322288
    323 
    324 === Win32 Issues ===
    325 If you run trac with mod_python < 3.2 on Windows, uploading attachments will '''not''' work. This problem is resolved in mod_python 3.1.4 or later, so please upgrade mod_python to fix this.
    326 
    327 
    328 === OS X issues ===
    329 
    330 When using mod_python on OS X you will not be able to restart Apache using `apachectl restart`. This is apparently fixed in mod_python 3.2, but there's also a patch available for earlier versions [http://www.dscpl.com.au/projects/vampire/patches.html here].
    331 
    332 === SELinux issues ===
    333 
    334 If Trac reports something like: ''Cannot get shared lock on db.lock''
    335 The security context on the repository may need to be set:
    336 
    337 {{{
     289=== Platform specific issues
     290==== Win32 Issues
     291
     292If you run Trac with mod_python < 3.2 on Windows, uploading attachments will '''not''' work. This problem is resolved in mod_python 3.1.4 or later, so please upgrade mod_python to fix this.
     293
     294==== OS X issues
     295
     296When using mod_python on OS X you will not be able to restart Apache using `apachectl restart`. This is apparently fixed in mod_python 3.2, so please upgrade mod_python to fix this.
     297
     298==== SELinux issues
     299
     300If Trac reports something like: `Cannot get shared lock on db.lock`, then the security context on the repository may need to be set:
     301
     302{{{#!sh
    338303chcon -R -h -t httpd_sys_content_t PATH_TO_REPOSITORY
    339304}}}
    340305
    341 See also [http://subversion.tigris.org/faq.html#reposperms]
    342 
    343 === FreeBSD issues ===
    344 Pay attention to the version of the installed mod_python and sqlite packages. Ports have both the new and old ones, but earlier versions of pysqlite and mod_python won't integrate as the former requires threaded support in python, and the latter requires a threadless install.
    345 
    346 If you compiled and installed apache2, apache wouldn´t support threads (cause it doesn´t work very well on FreeBSD). You could force thread support when running ./configure for apache, using --enable-threads, but this isn´t recommendable.
    347 The best option [http://modpython.org/pipermail/mod_python/2006-September/021983.html seems to be] adding to /usr/local/apache2/bin/ennvars the line
    348 
    349 {{{
     306See also [http://subversion.apache.org/faq.html#reposperms How do I set repository permissions correctly?]
     307
     308==== FreeBSD issues
     309
     310The FreeBSD ports have both the new and old versions of mod_python and SQLite, but earlier versions of pysqlite and mod_python won't integrate:
     311 * pysqlite requires threaded support in Python
     312 * mod_python requires a threadless install.
     313
     314Apache2 does not automatically support threads on FreeBSD. You could force thread support when running `./configure` for Apache, using `--enable-threads`, but this isn´t recommended.
     315The best option [http://modpython.org/pipermail/mod_python/2006-September/021983.html seems to be] adding to /usr/local/apache2/bin/ennvars the line:
     316
     317{{{#!sh
    350318export LD_PRELOAD=/usr/lib/libc_r.so
    351319}}}
    352320
    353 === Subversion issues ===
    354 
    355 If you get the following Trac Error `Unsupported version control system "svn"` only under mod_python, though it works well on the command-line and even with TracStandalone, chances are that you forgot to add the path to the Python bindings with the [TracModPython#ConfiguringPythonPath PythonPath] directive. (The better way is to add a link to the bindings in the Python `site-packages` directory, or create a `.pth` file in that directory.)
    356 
    357 If this is not the case, it's possible that you're using Subversion libraries that are binary incompatible with the apache ones (an incompatibility of the `apr` libraries is usually the cause). In that case, you also won't be able to use the svn modules for Apache (`mod_dav_svn`).
    358 
    359 You also need a recent version of `mod_python` in order to avoid a runtime error ({{{argument number 2: a 'apr_pool_t *' is expected}}}) due to the default usage of multiple sub-interpreters. 3.2.8 ''should'' work, though it's probably better to use the workaround described in [trac:#3371 #3371], in order to force the use of the main interpreter:
    360 {{{
     321==== Fedora 7 Issues
     322
     323Make sure you install the 'python-sqlite2' package as it seems to be required for TracModPython, but not for tracd.
     324
     325=== Subversion issues
     326
     327If you get the following Trac error `Unsupported version control system "svn"` only under mod_python, though it works well on the command-line and even with TracStandalone, chances are that you forgot to add the path to the Python bindings with the [TracModPython#ConfiguringPythonPath PythonPath] directive. A better way is to add a link to the bindings in the Python `site-packages` directory, or create a `.pth` file in that directory.
     328
     329If this is not the case, it's possible that you are using Subversion libraries that are binary incompatible with the Apache ones and an incompatibility of the `apr` libraries is usually the cause. In that case, you also won't be able to use the svn modules for Apache (`mod_dav_svn`).
     330
     331You also need a recent version of `mod_python` in order to avoid a runtime error ({{{argument number 2: a 'apr_pool_t *' is expected}}}) due to the default usage of multiple sub-interpreters. Version 3.2.8 ''should'' work, though it's probably better to use the workaround described in [trac:#3371 #3371], in order to force the use of the main interpreter:
     332{{{#!apache
    361333PythonInterpreter main_interpreter
    362334}}}
    363 This is anyway the recommended workaround for other well-known issues seen when using the Python bindings for Subversion within mod_python ([trac:#2611 #2611], [trac:#3455 #3455]). See in particular Graham Dumpleton's comment in [trac:comment:9:ticket:3455 #3455] explaining the issue.
    364 
    365 === Page layout issues ===
    366 
    367 If the formatting of the Trac pages look weird chances are that the style sheets governing the page layout are not handled properly by the web server. Try adding the following lines to your apache configuration:
    368 {{{
    369 #!xml
     335
     336This is also the recommended workaround for other issues seen when using the Python bindings for Subversion within mod_python ([trac:#2611 #2611], [trac:#3455 #3455]). See in particular Graham Dumpleton's comment in [trac:comment:9:ticket:3455 #3455] explaining the issue.
     337
     338=== Page layout issues
     339
     340If the formatting of the Trac pages look weird, chances are that the style sheets governing the page layout are not handled properly by the web server. Try adding the following lines to your Apache configuration:
     341{{{#!apache
    370342Alias /myproject/css "/usr/share/trac/htdocs/css"
    371343<Location /myproject/css>
     
    374346}}}
    375347
    376 Note: For the above configuration to have any effect it must be put after the configuration of your project root location, i.e. {{{<Location /myproject />}}}.
    377 
    378 Also, setting `PythonOptimize On` seems to mess up the page headers and footers, in addition to hiding the documentation for macros and plugins (see #Trac8956). Considering how little effect the option has, it is probably a good idea to leave it `Off`.
    379 
    380 === HTTPS issues ===
    381 
    382 If you want to run Trac fully under https you might find that it tries to redirect to plain http. In this case just add the following line to your apache configuration:
    383 {{{
    384 #!xml
    385 <VirtualHost * >
     348'''Note''': For the above configuration to have any effect it must be put after the configuration of your project root location, ie {{{<Location /myproject />}}}.
     349
     350Also, setting `PythonOptimize On` seems to mess up the page headers and footers, in addition to hiding the documentation for macros and plugins (see #Trac8956). Considering how little effect the option has, leave it `Off`.
     351
     352=== HTTPS issues
     353
     354If you want to run Trac fully under https you might find that it tries to redirect to plain http. In this case just add the following line to your Apache configuration:
     355{{{#!apache
     356<VirtualHost *>
    386357    DocumentRoot /var/www/myproject
    387358    ServerName trac.mycompany.com
     
    391362}}}
    392363
    393 === Fedora 7 Issues ===
    394 Make sure you install the 'python-sqlite2' package as it seems to be required for TracModPython but not for tracd
    395 
    396 
    397 === Segmentation fault with php5-mhash or other php5 modules ===
    398 You may encounter segfaults (reported on debian etch) if php5-mhash module is installed. Try to remove it to see if this solves the problem. See debian bug report [http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=411487]
    399 
    400 Some people also have troubles when using php5 compiled with its own 3rd party libraries instead of system libraries. Check here [http://www.djangoproject.com/documentation/modpython/#if-you-get-a-segmentation-fault]
     364=== Segmentation fault with php5-mhash or other php5 modules
     365
     366You may encounter segfaults (reported on Debian etch) if php5-mhash module is installed. Try to remove it to see if this solves the problem. See [http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=411487 Debian bug report].
     367
     368Some people also have troubles when using PHP5 compiled with its own third party libraries instead of system libraries. Check [http://www.djangoproject.com/documentation/modpython/#if-you-get-a-segmentation-fault Django segmentation fault].
    401369
    402370----
    403 See also:  TracGuide, TracInstall, [wiki:TracModWSGI ModWSGI], [wiki:TracFastCgi FastCGI],  [trac:TracNginxRecipe TracNginxRecipe]
     371See also: TracGuide, TracInstall, [wiki:TracModWSGI ModWSGI], [wiki:TracFastCgi FastCGI], [trac:TracNginxRecipe]