--- a/src/Preflight/RedispatchToSiteLocal.php	2020-06-27 19:47:36.803723363 +0200
+++ b/src/Preflight/RedispatchToSiteLocal.php	2020-06-27 19:49:29.210892351 +0200
@@ -45,18 +45,16 @@
             return false;
         }
 
+        if(dirname($argv[0]) == dirname($siteLocalDrush)) {
+            return false;
+        }
+
         // 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);
+        $ret = pcntl_exec($command, $argv);
+        $status = is_null($ret);
         return $status;
     }