I recently tried out the Siwapp invoicing system and had a few issues when getting it to install. It was working perfectly on another box however. The difference was that one was installed with PHP as an apache module, and the other installed with PHP as CGI.

To find out that this was my problem I ran the installer_dev.php instead of the installer.php file but first I had to edit the file from its standard to this: https://gist.github.com/848692. See the big red comment in the middle and the error_reporting function used at the start of the file.

On running the installer_dev.php file again and going to the 2nd step, it gave me the error “Fatal error: Call to undefined function apache_get_modules() in /path/to/apps/installer/lib/checks.class.php“. The problem is caused by the apache_get_modules() not working with PHP installed as CGI.

So I went to that file opened it up and commented out the section that checked for installed apache modules. You can see the result here: https://gist.github.com/848705

After I did that I found I was missing an htaccess file in the web directory so I found this off the discussion group: https://gist.github.com/848708

Last but no least the config.php in the web root didn’t have the correct sf_root_dir though that might be my fault – check it anyway.

After those changes it was away… easy.