Composer爲什麼安裝似乎與要求衝突的軟件包版本？

Question

這看起來像一個簡單的問題，但我無法解釋發生了什麼。

在我的Symfony項目的composer.json中，樹枝版本被指定爲< 2.0，以避免破壞v1和v2之間的變化。但是，Composer無論如何安裝最新的Twig版本（2.4.3）。

php c:\php\composer\composer.phar depends -t "twig/twig" 
twig/twig v2.4.3 Twig, the flexible, fast, and secure template language for PHP 
|--symfony/framework-standard-edition dev-develop (requires twig/twig <2.0) 
|--symfony/symfony v2.8.24 (requires twig/twig ~1.34|~2.4) 
| `--symfony/framework-standard-edition dev-develop (requires symfony/symfony 2.8.*) 
`--twig/extensions v1.5.1 (requires twig/twig ~1.27|~2.0) 
    `--symfony/framework-standard-edition dev-develop (requires twig/extensions ^1.3) 

composer.json的相關大塊：

"require": { 
    "php": ">=5.3.3", 
    "symfony/symfony": "2.8.*", 
    "doctrine/dbal": "2.5.*", 
    "doctrine/orm": "2.5.*", 
    "doctrine/doctrine-bundle": "~1.2", 
    "twig/twig": "<2.0", 
    "twig/extensions": "^1.3", 
    etc 
} 

在我看來像symfony/symfony和twig/extensions包裝的要求，與項目相結合，會造成最高可能1。 x版本的Twig，1.34.4，但這不是什麼情況。爲什麼？

編輯：

作曲家1.4.2

完全composer.json

{ 
    "name": "symfony/framework-standard-edition", 
    "license": "MIT", 
    "type": "project", 
    "description": "The \"Symfony Standard Edition\" distribution", 
    "autoload": { 
     "psr-0": { "": "src/", "SymfonyStandard": "app/" } 
    }, 
    "require": { 
     "php": ">=5.3.3", 
     "symfony/symfony": "2.8.*", 
     "doctrine/dbal": "2.5.*", 
     "doctrine/orm": "2.5.*", 
     "doctrine/doctrine-bundle": "~1.2", 
     "twig/twig": "<2.0", 
     "twig/extensions": "^1.3", 
     "symfony/assetic-bundle": "^2.8", 
     "symfony/swiftmailer-bundle": "~2.3", 
     "symfony/monolog-bundle": "~2.4", 
     "sensio/distribution-bundle": "~3.0", 
     "sensio/framework-extra-bundle": "~3.0", 
     "incenteev/composer-parameter-handler": "~2.0", 
     "beberlei/DoctrineExtensions": "^1.0", 
     "royopa/fpdf-symfony2": "^1.0", 
     "liuggio/excelbundle": "^2.0", 
     "patchwork/jsqueeze": "^2.0", 
     "leafo/scssphp": "^0.6.5", 
     "doctrine/doctrine-migrations-bundle": "^1.0", 
     "ocramius/proxy-manager": "~2.0.0", 
     "aws/aws-sdk-php-symfony": "^1.2" 
    }, 
    "require-dev": { 
     "sensio/generator-bundle": "~2.3", 
     "symfony/phpunit-bridge": "^3.1", 
     "deployer/deployer": "^3.3" 
    }, 
    "scripts": { 
     "post-root-package-install": [ 
      "SymfonyStandard\\Composer::hookRootPackageInstall" 
     ], 
     "post-install-cmd": [ 
      "Sensio\\Bundle\\DistributionBundle\\Composer\\ScriptHandler::buildBootstrap", 
      "Sensio\\Bundle\\DistributionBundle\\Composer\\ScriptHandler::clearCache", 
      "Sensio\\Bundle\\DistributionBundle\\Composer\\ScriptHandler::installAssets", 
      "Sensio\\Bundle\\DistributionBundle\\Composer\\ScriptHandler::installRequirementsFile", 
      "Sensio\\Bundle\\DistributionBundle\\Composer\\ScriptHandler::removeSymfonyStandardFiles" 
     ], 
     "post-update-cmd": [ 
      "Sensio\\Bundle\\DistributionBundle\\Composer\\ScriptHandler::buildBootstrap", 
      "Sensio\\Bundle\\DistributionBundle\\Composer\\ScriptHandler::clearCache", 
      "Sensio\\Bundle\\DistributionBundle\\Composer\\ScriptHandler::installAssets", 
      "Sensio\\Bundle\\DistributionBundle\\Composer\\ScriptHandler::installRequirementsFile", 
      "Sensio\\Bundle\\DistributionBundle\\Composer\\ScriptHandler::removeSymfonyStandardFiles" 
     ] 
    }, 
    "config": { 
     "bin-dir": "bin" 
    }, 
    "extra": { 
     "symfony-app-dir": "app", 
     "symfony-web-dir": "web", 
     "incenteev-parameters": { 
      "file": "app/config/parameters.yml" 
     }, 
     "branch-alias": { 
      "dev-master": "2.5-dev" 
     } 
    } 
} 

編輯2：

刪除composer.lock完全更新並重新安裝給了我什麼，我想我應該得到！

Answer 1

您使用的是什麼版本的作曲家？

我在Linux Mint 17上測試了這個json文件，使用php 5.5和composer 1.3.2，安裝的twig版本是正確的（twig/twig - v1.34.4）。

你可以嘗試粘貼你的完整composer.json文件嗎？

此外，我建議刪除composer.lock文件和供應商文件夾的所有內容，然後再次嘗試安裝。