drupal_alter in page_manager_load_task_handlers()

ctools-page_manager_load_task_handlers_alter.patch

diff --git page_manager/page_manager.module page_manager/page_manager.module
index 7b606af..4200315 100644
--- page_manager/page_manager.module
+++ page_manager/page_manager.module
@@ -530,6 +530,9 @@ function page_manager_load_task_handlers($task, $subtask_id = NULL, $default_han
     }
   }
 
+  // Let other modules alter the handlers.
+  drupal_alter('page_manager_load_task_handlers', $handlers, $task, $subtask_id);
+
   return $handlers;
 }

my-feature.module.php

<?php
/**
 * @file
 * Code for the my-feature feature.
 */

include_once 'my_feature.features.inc';

/**
 * Implements hook_page_manager_load_task_handlers_alter().
 *
 * When page manager loads task handlers for pages we remove the page handlers
 * that are handled by features in this module.
 *
 * Requires a patch to ctools/page_manager.module (call drupal_alter).
 */
function my_feature_page_manager_load_task_handlers_alter(&$handlers, $task, $subtask_id = NULL) {
  // If we are on an admin/structure/features* page or we are being called
  // through drush features we will filter out page handlers.
  $in_drush_features = FALSE;

  if (function_exists('drush_get_command')) {
    $command = drush_get_command();
    if (isset($command['drupal dependencies']) && in_array('features', $command['drupal dependencies'])) {
      $in_drush_features = TRUE;
    }
  };

  if (preg_match('/admin\/structure\/features/', $_GET['q']) || $in_drush_features) {
    // Load the page handlers handled by this feature module.
    $my_feature_handlers = array_keys(my_feature_default_page_manager_handlers());

    if ($task['name'] == 'page') {
      foreach ($handlers as $handler) {
        if (in_array($handler->name, $my_feature_handlers)) {
          unset($handlers[$handler->name]);
        }
      }
    }
  }
}