Composer Memory Size Fatal Error – How to Fix

The problem comes from .htaccess. One of the values is php_value memory_limit 256M. This doesn't make sense on the first view, but on the second it is explainable.

I don't know why magento implemented this idiot thing, but what happend is, the following method reads the information from .htaccess and processes them:

\Mage_Shell_Abstract::_applyPhpVariables
protected function _applyPhpVariables()
{
    $htaccess = $this->_getRootPath() . '.htaccess';
    if (file_exists($htaccess)) {
        // parse htaccess file
        $data = file_get_contents($htaccess);
        $matches = array();
        preg_match_all('#^\s+?php_value\s+([a-z_]+)\s+(.+)$#siUm', $data, $matches, PREG_SET_ORDER);
        if ($matches) {
            foreach ($matches as $match) {
                @ini_set($match[1], str_replace("\r", '', $match[2]));
            }
        }
        preg_match_all('#^\s+?php_flag\s+([a-z_]+)\s+(.+)$#siUm', $data, $matches, PREG_SET_ORDER);
        if ($matches) {
            foreach ($matches as $match) {
                @ini_set($match[1], str_replace("\r", '', $match[2]));
            }
        }
    }
}

It looks to me based on what you state at the start (run reindex all) that you are currently using the command line shell/index.php to do your reindexing.

In the default configuration of servers, PHP runs two ini files one which deals with command line, and one which deals with your web server. So the .htaccess information would not actually be used.

Depending on your server configuration, there are a few places that the file may exist so if you have a look in

/etc/php

/etc/php5

You will hopefully find a sub directory structure which reveals a cli folder perhaps under conf.d and within that you will have the php.ini file which is used to configure the CLI tool you are using. This file needs to have the value for memory_limit increased.

If you run a phpinfo() from the CLI you may find it will tell you in the output the actual ini file loaded (and of course the information to do with the current values.

Hope that helps.