Can't install mongodb doctrine in symfony2 with composer

Question

I\'ve followed the official documentation

when I run composer update I have this error : Your requirements could not be resolved to an installable set of packages.

Answer 1

for OSX:

brew install php56-mongo

if it errors out: read the error message carefully and follow it to rerun the command.

source:

http://php.net/manual/en/mongo.installation.php#mongo.installation.osx