Login to Magento admin with MAMP

Magento need cookies to works and most of the browser don't set cookies for local website.

Here is the solution to get it works on MacOSX :

Just open the app\code\core\Mage\Core\Model\Session\Abstract\Varien.php

change the line 107

if (isset($cookieParams['domain'])) { 

to

if (isset($cookieParams['domain']) && !in_array("::1", self::getValidatorData())) {

Then go to your /admin and log in your backoffice !