composer/laravel -- mbstring: installed, available, but not seen by laravel

Question: How does composer/laravel know, or not know, that mbstring is installed? What do I need to do to point composer/laravel at mbstring?

Trying to install latest / greatest larvel onto a RHEL server. mbstring is installed and enabled in both GUI and CLI.

ie cli:

/usr/bin/php -v:
PHP 5.5.24 (cli) (built: Apr 18 2015 03:23:49)
Copyright (c) 1997-2015 The PHP Group
Zend Engine v2.5.0, Copyright (c) 1998-2015 Zend Technologies

and

/usr/bin/php -m
[PHP Modules]
...
mbstring
mcrypt
...

Yet when I do this:

$ composer create-project --prefer-dist laravel/laravel dev-laravel
Installing laravel/laravel (v5.2.15)
  - Installing laravel/laravel (v5.2.15)
    Loading from cache

I get this:

Problem 1
    - laravel/framework v5.2.9 requires ext-mbstring * -> the requested PHP extension mbstring is missing from your system.

Well, I get like 20 of them.

I have searched stack/web and everybody solves the issue of "installing" mbstring ... That's not my problem. I know it working based upon using code that requires mbstring to be installed and working.

The only thing that seems wrong is that in php.ini extension_dir is not enabled.

ie:

 ; extension_dir = "./"

But enabling that breaks the current install.

So I am guessing that composer/laravel just can't find mbstring ...

via Chebli Mohamed