Error on Craft 3 install When attempting to install Craft 3 in OSX El Cap, I'm getting the following errors:


  Script @php craft setup/welcome handling the post-create-project-cmd event returned with error code 255
  /Craft3/vendor/craftcms/cms/bootstrap/bootstrap.php on line 104
  
  Parse error: parse error in PATH/vendor/craftcms/cms/bootstrap/bootstrap.php on line 104
  Script @php craft setup/welcome handling the post-create-project-cmd event returned with error code 255


I used the --ignore-platform-reqs flag as I am using PHP7 on MAMP.

When I attempt to load index.php in the browser I'm seeing this seemingly related issue in the trace:


  in PATH/web/index.php at line 21 – yii\base\Application::run() 15161718192021    (new Dotenv\Dotenv(CRAFT_BASE_PATH))->load();}
  
  // Load and run Craft
  define('CRAFT_ENVIRONMENT', getenv('ENVIRONMENT') ?: 'production');
  $app = require CRAFT_VENDOR_PATH.'/craftcms/cms/bootstrap/web.php';
  $app->run();


I've substituted "PATH" in all errors in lieu of the actual path.

Any advice on resolving this would be much appreciated.
In order to install under MAMP with PHP7 we added the MAMP PHP7 path with the following command:


  export PATH="/Applications/MAMP/bin/php/php7.0.15/bin:$PATH"


After achieving a successful Craft 3 install we ran the setup in the CLI and we also created a fresh DB and a new MAMP host following the sequence recommended in the installation docs.