Index: drush/src/Preflight/RedispatchToSiteLocal.php
===================================================================
--- a/src/Preflight/RedispatchToSiteLocal.php
+++ b/src/Preflight/RedispatchToSiteLocal.php
@@ -30,7 +30,7 @@ class RedispatchToSiteLocal
     {
 
         // Try to find the site-local Drush. If there is none, we are done.
-        $siteLocalDrush = static::findSiteLocalDrush($root);
+        $siteLocalDrush = realpath(static::findSiteLocalDrush($root));
         if (!$siteLocalDrush) {
             return [false, DrushCommands::EXIT_SUCCESS];
         }
@@ -46,18 +46,38 @@ class RedispatchToSiteLocal
             return [false, DrushCommands::EXIT_SUCCESS];
         }
 
+        if (dirname($argv[0]) == dirname($siteLocalDrush)) {
+            return [false, DrushCommands::EXIT_SUCCESS];
+        }
+
+        if(array_key_exists('_composer_bin_dir', $GLOBALS) &&
+            dirname($argv[0]) == $GLOBALS['_composer_bin_dir']) {
+            return [false, DrushCommands::EXIT_SUCCESS];
+        }
+
         // Redispatch!
-        $command = escapeshellarg($siteLocalDrush);
-        $preflightLog->log(dt('Redispatch to site-local Drush: !cmd.', ['!cmd' => $command]));
-        array_shift($argv);
-        $args = array_map(
-            function ($item) {
-                return escapeshellarg($item);
-            },
-            $argv
-        );
-        $command .= ' ' . implode(' ', $args);
-        passthru($command, $status);
+        print 'DEBUG: Redispatch!' . PHP_EOL;
+
+        // We have to reconstruct the whole command line, because
+        // at this point, we will take over the control on running the Drush command
+        $command = PHP_BINARY;
+        // Add some PHP arguments
+        // TODO Implement it at the SiteAlias\ProcessManager too
+        $php_args = [
+          '-d', 'memory_limit=-1',
+          '-d', 'allow_url_fopen=1',
+          '-d', 'display_errors=1',
+          '-d', 'error_reporting=' . strval(E_ALL & ~E_NOTICE & ~E_DEPRECATED),
+        ];
+
+        $args = array_merge($php_args, $argv);
+        print_r(['command' => $command, 'args' => $args, 'siteLocalDrush' => $siteLocalDrush]);
+
+        $preflightLog->log(dt('Redispatch to site-local Drush: !cmd.', ['!cmd' => $argv[0]]));
+
+        $ret = pcntl_exec($command, $args);
+        $status = is_null($ret);
+
 
         return [true, $status];
     }
Index: drush/src/SiteAlias/ProcessManager.php
===================================================================
--- a/src/SiteAlias/ProcessManager.php
+++ b/src/SiteAlias/ProcessManager.php
@@ -63,6 +63,21 @@ class ProcessManager extends Consolidati
         // The executable is always 'drush' (at some path or another)
         array_unshift($args, $drushScript);
 
+        // TODO Implement some PHP argument bypassing
+        $essential_php_args = [
+          'allow_url_fopen' => 1,
+          'memory_limit' => ini_get('memory_limit'),
+        ];
+
+        foreach($essential_php_args as $key => $value) {
+          array_unshift($args, "{$key}={$value}");
+          array_unshift($args, '-d');
+        }
+
+        if($drushScript != 'drush' && defined('PHP_BINARY')) {
+          array_unshift($args, PHP_BINARY);
+        }
+
         return $this->siteProcess($siteAlias, $args, $options, $options_double_dash);
     }