php artisan clear-compiled failing

I cloned an existing laravel5 project from github repository. in my root using Mac terminal I ran composer install I got out put of dependency installation and at some point when output reached

> php artisan clear-compiled

I got the following error

Fatal error: Cannot redeclare createDirIfNotExist() (previously declared in /Users/applebook/projects/referral-system/Laravel5/laravel/config/constants.php:14) in /Users/applebook/projects/referral-system/Laravel5/laravel/config/constants.php on line 20

Script php artisan clear-compiled handling the pre-update-cmd event returned with an error

I'm stuck here since past few hours, nothing is working out. any command artisan , php artisan --version composer update is giving me same error.

Can anyone help me get through this ? Also if anybody suggest me a good tutorial setting up existing laravel5 project on mac os x ?

via Chebli Mohamed