<p>Échec de l'installation du compositeur avec erreur : échec de l'ouverture du flux : opération en cours</p>

Mon composer.json :

{
    "require": {
        "fxp/composer-asset-plugin": "~1.1.1"
    }
}

quand je cours
php -r "readfile('https://packagist.phpcomposer.com/packages.json');" > composer-setup.php PHP Warning: readfile(https://packagist.phpcomposer.com/packages.json): failed to open stream: Operation now in progress in Command line code on line 1
et je lance le code anthoer

LiuZeXin:GA xin$ composer global require "fxp/composer-asset-plugin:~1.1.1"
Changed current directory to /Users/xin/.composer
./composer.json has been updated
Loading composer repositories with package information

Installation failed, reverting ./composer.json to its original content.


  [Composer\Downloader\TransportException]
  **The "https://packagist.phpcomposer.com/packages.json" file could not be downloaded: failed to open stream: Operation now in progress**


require [--dev] [--prefer-source] [--prefer-dist] [--no-progress] [--no-update] [--no-scripts] [--update-no-dev] [--update-with-dependencies] [--ignore-platform-reqs] [--prefer-stable] [--prefer-lowest] [--sort-packages] [-o|--optimize-autoloader] [-a|--classmap-authoritative] [--] [<packages>]...

Je pense qu'il s'agit d'une erreur de configuration des paramètres dans php.ini.
J'ai besoin d'aide.