当我运行composer.phar安装时，一切似乎都很好：
→ sudo php composer.phar install
Loading composer repositories with package information
Installing dependencies (including require-dev) from lock file
Nothing to install or update
Generating autoload files
Clearing the cache for the dev environment with debug true
Installing assets using the hard copy option
Installing assets for SymfonyBundleFrameworkBundle into web/bundles/framework
Installing assets for FOSJsRoutingBundle into web/bundles/fosjsrouting
etc etc
但是现在，我想安装此捆绑包：https://github.com/KnpLabs/KnpPaginatorBundle 来自 https://packagist.org/packages/knplabs/knp-paginator-bundle
所以我用新的要求行更新了 composer.json 文件。
{
"require": {
"knplabs/knp-paginator-bundle": "v2.1"
}
}
（我已经尝试了Packegist的每个版本的Paginator，但仍然出现相同的错误）
然后我尝试安装它：
→ sudo php composer.phar install
Loading composer repositories with package information
Installing dependencies (including require-dev) from lock file
Warning: The lock file is not up to date with the latest changes in composer.json. You may be getting outdated dependencies. Run update to update them.
Your requirements could not be resolved to an installable set of packages.
Problem 1
- Installation request for symfony/framework-standard-edition 2.1.x-dev -> satisfiable by symfony/framework-standard-edition[2.1.x-dev].
- symfony/framework-standard-edition 2.1.x-dev requires knplabs/knp-paginator-bundle v2.1 -> no matching package found.
Potential causes:
- A typo in the package name
- The package is not available in a stable-enough version according to your minimum-stability setting
see <https://groups.google.com/d/topic/composer-dev/_g3ASeIFlrc/discussion> for more details.
Read <http://getcomposer.org/doc/articles/troubleshooting.md> for further common problems.
还有我当前作曲家.json的symfony2行：
"require": {
"php": ">=5.3.3",
"symfony/symfony": "2.1.*",
"doctrine/orm": ">=2.2.3,<2.4-dev",
"symfony/symfony": "2.1.x-dev" did not help
请问我该怎么办？
你应该在项目目录中运行以下命令：
php composer.phar update
几个小时后，我终于找到了解决方案！
我不知道我的 composer.json 依赖项是否以某种方式不是最佳状态，但解决我问题的是仅更新和安装所需的捆绑包！
呜呜???我刚才说了什么???是的，只有所需的捆绑包，所以...
sudo php composer.phar require
然后只需通过作曲家酷搜索找到您的欲望捆绑 https://packagist.org .
从列表中选择数字并填写版本。
它将下载捆绑包，更新 composer.json 和 composer.lock 文件:)
希望这个答案能帮助到某人！