apt-get update – is your friend!

Problem:
I ran into a GD Image library error because the Turnkey Linux Drupal 6 Appliance (v 11.2) did not have PHP with GD compiled.

Solution:

1. Used “apt-get update” command from terminal to update packages.
2. Then I ran the “apt-get install php5-gd” command.  Bang!  GD Library is available and ready to use for Drupal 6.22.