Upgrade to VisualSVN Server 5.4.0 fails because the mod_wsgi module could not be found

Applies to: VisualSVN Server 5.4 or later

Symptoms

An upgrade to VisualSVN Server 5.4.0 or later may fail, displaying the error message Failed to start HTTP service, accompanied by the following entry in the 'VisualSVN Server' event log:

vsvnhttpsvc.exe: Syntax error on line 194 of C:/Program Files/VisualSVN Server/conf/httpd.conf: Syntax error on line 1 of C:/Program Files/VisualSVN Server/conf/httpd-custom.conf:
Cannot load bin/mod_wsgi.so into server: The specified module could not be found.

Upon displaying this error, the installer will roll back to the previously installed version of VisualSVN Server.

Tip

You can find the error message in the 'VisualSVN Server' event log:

  1. Start Event Viewer (eventvwr.msc).
  2. Click Applications and Services Logs.
  3. Click VisualSVN Server.
  4. Examine the log to find the error message.

Cause

The service startup error occurs when upgrading to VisualSVN Server 5.4.0 or later that was customized to load an optional module mod_wsgi in the configuration file %VISUALSVN_SERVER%conf\httpd-custom.conf. Starting from version 5.4.0, the mod_wsgi module is no longer installed by default. The upgrade to version 5.4.x removes the module by default too.

You can determine if the server was customized to load the mod_wsgi module by looking for the following line in the httpd-custom.conf file: 

LoadModule wsgi_module bin/mod_wsgi.so

This line is usually accompanied with other configuration directives in the configuration file such as WSGIScriptAlias, WSGIApplicationGroup, WSGIAuthUserScript. All directive names used by the module start with WSGI.

Resolution

To resolve the problem, it is recommended to remove the customizations related to the mod_wsgi module. If the customization is obsolete and no longer needed, clean up the file and remove the customizations. Then start the installer again and the upgrade should finish successfully.

If removing the customizations related to the mod_wsgi module isn't possible in your case, please contact support@visualsvn.com for further assistance.

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