ComposerコマンドからLaravelプロジェクトを作成した際のエラー

$ composer create-project laravel/laravel --prefer-dist
Installing laravel/laravel (v5.0.1)
  - Installing laravel/laravel (v5.0.1)
    Loading from cache

Created project in .
Loading composer repositories with package information
Installing dependencies (including require-dev)


                                                                                                                                      
  [RuntimeException]                                                                                                                  
  Could not load package dragonrun1/phpspec in http://packagist.org: [UnexpectedValueException] Could not parse version constraint ^  
  1.0.1: Invalid version string "^1.0.1"                                                                                              
                                                                                                                                      




                                                                              
  [UnexpectedValueException]                                                  
  Could not parse version constraint ^1.0.1: Invalid version string "^1.0.1"  
                                                                              


create-project [-s|--stability="..."] [--prefer-source] [--prefer-dist] [--repository-url="..."] [--dev] [--no-dev] [--no-plugins] [--no-custom-installers] [--no-scripts] [--no-progress] [--keep-vcs] [--no-install] [package] [directory] [version]

ComposerコマンドからLaravelプロジェクトを作成した際
上記のようなエラーが出た。

composerが古いのが原因のよう
アップデートすると解決した。

$ composer selfupdate
Updating to version d57187446151ef84b28cb9f6b3ed38cc2cffc597.
    Downloading: 100%         
Use composer self-update --rollback to return to version 1.0.0-alpha9

$ composer update