We receive this error very frequently in the logs of all clients who are hosted in hosts where the php.ini setting open_basedir is active:
DATE Monday, December 23, 2013 - 15:52
MESSAGE Warning: curl_setopt(): CURLOPT_FOLLOWLOCATION cannot be activated when safe_mode is enabled or an open_basedir is set in CRM_Utils_HttpClient->createCurl() (line 192 of /var/www/vhosts/site.ca/httpdocs/sites/all/modules/civicrm/CRM/Utils/HttpClient.php).
This error occurs on the front page of civicrm, on the extensions page I think and also when using some of the core payment processors that are using curl.
It is a minor warning that is not stopping anything from working but it does fill up the logs. it also means that if a redirect was actually needed then it wouldn't work. We did quite a bit of research to see if there are any other settings we could change to avoid this while still leaving open_basedir activated but didn't find a settings based solution.
The only solutions found indicate the need to modify the Http Client code using a manually coded redirect (if needed) such as:
One option might be to move away from using the Pear library and use this client library which will apparently be used by Drupal 8:
I did a search of the github code for Guzzle and it does not appear to use CURLOPT_FOLLOWLOCATION.