GD uses the function imagerotate
. According to this answer on stackoverflow the function isn’t included on some OS’es because of a memory leak. This problem is also mentioned as comment in the WordPress code:
On some setups GD library does not provide imagerotate() – Ticket #11536
The ticket number belongs to the WordPress Ticket #11536.
As a solution you can try to use the workaround mentioned in the stackoverflow answer or you can install php-imagick as an alternative to gd, which is also supported by WordPress.