Using Kolab_Development packages under CentOS 7, the web client throws fatal errors when opening the calendar because Sabre/VObject classes are not found. It appears that the Composer autoloader is not built correctly during packaging. Similar to #iRony or other projects, a stub `composer.json` file with path definitions to `/usr/share/...` should be used for building:
```
{
"name": "kolab/roundcubemail",
"description": "Roundcube Webmail for Kolab",
"license": "GPL-3.0",
"require": {
"php": ">=5.3.3"
},
"autoload": {
"psr-0": {
"": "/usr/share/pear/"
},
"psr-4": {
"": "/usr/share/php/"
}
}
}
```