Php 从composer创建Symfony2项目时出错

我尝试使用以下命令在Ubuntu上使用composer创建Symfony2项目：

php composer.phar create-project symfony/framework-standard-edition projectpath

我得到了这个错误

Installing symfony/framework-standard-edition (dev-master 506ffaab8d8474db2512fca879ca4b9877616a1e)
  - Installing symfony/framework-standard-edition (dev-master master)
    Cloning master

Created project in projectpath/
Loading composer repositories with package information
Installing dependencies from lock file
Your lock file is out of sync with your composer.json, run "composer.phar update" to update dependencies
Your requirements could not be resolved to an installable set of packages.

  Problem 1
    - Installation request for symfony/symfony == 2.1.9999999.9999999-dev -> satisfiable by symfony/symfony 2.1.x-dev.
    - Can only install one of: symfony/symfony dev-master, symfony/symfony 2.1.x-dev.
    - Installation request for symfony/symfony == 9999999-dev -> satisfiable by symfony/symfony dev-master.

composer.phar更新也会返回一个错误

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有什么想法吗？

请尝试指定您想要的确切版本，它现在已在symfony标准回购协议中修复，这应该可以：

 php composer.phar create-project symfony/framework-standard-edition projectpath 2.1.x-dev

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尝试删除你的composer.lock文件。你试过按它所说的做吗？也就是说：

php composer.phar update

在安装之前？是的，它还返回一个错误：您的需求无法解析为一组可安装的包。问题1-symfony/monolog bundle v2.1.0-BETA1需要symfony/config 2.1.*->可满足。。。