commit 9ea180876a38131fac180af38271e86f06d664b1
Author: Randy Fay <randy@randyfay.com>
Date:   Thu Aug 4 15:45:34 2011 -0600

    Issue #1158820 by rfay: hook_requirements cannot use database

diff --git a/amazon.install b/amazon.install
index fbda0b6..589ad21 100644
--- a/amazon.install
+++ b/amazon.install
@@ -34,9 +34,12 @@ function amazon_uninstall() {
  * implementation of hook_requirements to make sure we let them know about
  * the requirement for amazon_aws_secret_access_key
  * @param $phase
- * @return unknown_type
+ * @return A $requirement[] array, or NULL if there are no issues.
  */
 function amazon_requirements($phase) {
+  if ($phase != 'runtime') {
+    return;
+  }
   $secret_access_key = variable_get('amazon_aws_secret_access_key', "");
   $api_key = variable_get('amazon_aws_access_key', "");
   $requirement = array();