I get an error when trying to use artisan command tinker. For example I would like to add a user. In my terminal I type
$ php artisan tinker
I personally use MAMP and also rely on MAMP's version of PHP for the CLI. When I hit this issue I found that the Redline and PCNTL extensions were not part of MAMP's PHP distribution.
I wrote an article on how I fixed the problem as well as a link to download the two extensions that I had to compile from source.
http://adampatterson.ca/blog/2014/10/laravel-tinker-boris-mamp-os-x-yosemite/