安装失败

Question

我把我的laravel安装从我的远程服务器拉到我的本地机器上，现在我想执行“composer”来安装所有所需的软件包。这件事在过去很顺利。但现在我收到了这个错误：

• *symfony/dom-爬虫2.7.x-dev、v2.7.0、v2.7.0-BETA1、v2.7.0-BETA2、v2.7.1、v2.7.10、v2.7.11、v2.7.12、v2.7.13、v2.7.14、v2.7.15、v2.7.16、v2.7.17、v2.7.18、v2.7.19、v2.7.2，v2.7.3，v2.7.4，v2.7.5，v2.7.6，v2.7.7，v2.7.8，v2.7.9，但这些都与您的要求或最低稳定性相冲突。

我的composer.json看起来是这样的：

> {
>     "name": "laravel/laravel",
>     "description": "The Laravel Framework.",
>     "keywords": ["framework", "laravel"],
>     "license": "MIT",
>     "type": "project",
>     "require": {
>         "php": ">=5.5.9",
>         "laravel/framework": "5.2.*",
>         "league/fractal": "^0.12.0",
>         "pda/pheanstalk": "^3.1",
>         "witty/laravel-push-notification": "dev-master",
>         "illuminate/html": "^5.0",
>         "way/generators": "^3.0",
>         "laracasts/generators": "^1.1"
>     },
>     "require-dev": {
>         "fzaninotto/faker": "~1.4",
>         "mockery/mockery": "0.9.*",
>         "phpunit/phpunit": "~4.0",
>         "phpspec/phpspec": "~2.1",
>         "symfony/dom-crawler": "~3.0"
>     },
>     "autoload": {
>         "classmap": [
>             "database"
>         ],
>         "psr-4": {
>             "App\\": "app/"
>         }
>     },
>     "autoload-dev": {
>         "classmap": [
>             "tests/TestCase.php"
>         ]
>     },
>     "scripts": {
>         "post-install-cmd": [
>             "php artisan clear-compiled",
>             "php artisan optimize"
>         ],
>         "pre-update-cmd": [
>             "php artisan clear-compiled"
>         ],
>         "post-update-cmd": [
>             "php artisan optimize"
>         ],
>         "post-root-package-install": [
>             "php -r \"copy('.env.example', '.env');\""
>         ],
>         "post-create-project-cmd": [
>             "php artisan key:generate"
>         ]
>     },
>     "config": {
>         "preferred-install": "dist"
>     } }

我没有改变我的代码，但我只是做了一个干净的安装我的计算机。

当我试图更改为dom-爬行器~2.7时，我得到了以下错误：

>  Problem 1
>     - Conclusion: don't install laravel/framework v5.2.45
>     - Conclusion: don't install laravel/framework v5.2.44
>     - Conclusion: don't install laravel/framework v5.2.43
>     - Conclusion: don't install laravel/framework v5.2.42
>     - Conclusion: don't install laravel/framework 5.2.41
>     - Conclusion: don't install laravel/framework v5.2.40
>     - Conclusion: don't install laravel/framework v5.2.39
>     - Conclusion: don't install laravel/framework v5.2.38
>     - Conclusion: don't install laravel/framework v5.2.37
>     - Conclusion: don't install laravel/framework v5.2.36
>     - Conclusion: don't install laravel/framework v5.2.35
>     - Conclusion: don't install laravel/framework v5.2.34
>     - Conclusion: don't install laravel/framework v5.2.33
>     - Conclusion: don't install laravel/framework v5.2.32
>     - Conclusion: don't install laravel/framework v5.2.31
>     - Conclusion: don't install laravel/framework v5.2.30
>     - Conclusion: don't install laravel/framework v5.2.29
>     - Conclusion: don't install laravel/framework v5.2.28
>     - Conclusion: don't install laravel/framework v5.2.27
>     - Conclusion: don't install laravel/framework v5.2.26
>     - Conclusion: don't install laravel/framework v5.2.25
>     - Conclusion: don't install laravel/framework v5.2.24
>     - Conclusion: don't install laravel/framework v5.2.23
>     - Conclusion: don't install laravel/framework v5.2.22
>     - Conclusion: don't install laravel/framework v5.2.21
>     - Conclusion: don't install laravel/framework v5.2.20
>     - Conclusion: don't install laravel/framework v5.2.19
>     - Conclusion: don't install laravel/framework v5.2.18
>     - Conclusion: don't install laravel/framework v5.2.17
>     - Conclusion: don't install laravel/framework v5.2.16
>     - Conclusion: don't install laravel/framework v5.2.15
>     - Conclusion: don't install laravel/framework v5.2.14
>     - Conclusion: don't install laravel/framework v5.2.13
>     - Conclusion: don't install laravel/framework v5.2.12
>     - Conclusion: don't install laravel/framework v5.2.11
>     - Conclusion: don't install laravel/framework v5.2.10
>     - Conclusion: don't install laravel/framework v5.2.9
>     - Conclusion: don't install laravel/framework v5.2.8
>     - Conclusion: don't install laravel/framework v5.2.7
>     - Conclusion: don't install laravel/framework v5.2.6
>     - Conclusion: don't install laravel/framework v5.2.5
>     - Conclusion: don't install laravel/framework v5.2.4
>     - Conclusion: don't install laravel/framework v5.2.3
>     - Conclusion: don't install laravel/framework v5.2.2
>     - Conclusion: don't install laravel/framework v5.2.1
>     - witty/laravel-push-notification dev-master requires illuminate/support 5.0.* | 5.1.* -> satisfiable by
> laravel/framework[v5.1.17], illuminate/support[v5.0.0, v5.0.22,
> v5.0.25, v5.0.26, v5.0.28, v5.0.33, v5.0.4, v5.1.1, v5.1.13, v5.1.16,
> v5.1.2, v5.1.20, v5.1.22, v5.1.25, v5.1.28, v5.1.30, v5.1.31, v5.1.41,
> v5.1.6, v5.1.8].
>     - witty/laravel-push-notification dev-master requires illuminate/support 5.0.* | 5.1.* -> satisfiable by
> laravel/framework[v5.1.17], illuminate/support[v5.0.0, v5.0.22,
> v5.0.25, v5.0.26, v5.0.28, v5.0.33, v5.0.4, v5.1.1, v5.1.13, v5.1.16,
> v5.1.2, v5.1.20, v5.1.22, v5.1.25, v5.1.28, v5.1.30, v5.1.31, v5.1.41,
> v5.1.6, v5.1.8].
>     - Can only install one of: laravel/framework[v5.2.0, v5.1.17].
>     - don't install illuminate/support v5.0.0|don't install laravel/framework v5.2.0
>     - don't install illuminate/support v5.0.22|don't install laravel/framework v5.2.0
>     - don't install illuminate/support v5.0.25|don't install laravel/framework v5.2.0
>     - don't install illuminate/support v5.0.26|don't install laravel/framework v5.2.0
>     - don't install illuminate/support v5.0.28|don't install laravel/framework v5.2.0
>     - don't install illuminate/support v5.0.33|don't install laravel/framework v5.2.0
>     - don't install illuminate/support v5.0.4|don't install laravel/framework v5.2.0
>     - don't install illuminate/support v5.1.1|don't install laravel/framework v5.2.0
>     - don't install illuminate/support v5.1.13|don't install laravel/framework v5.2.0
>     - don't install illuminate/support v5.1.16|don't install laravel/framework v5.2.0
>     - don't install illuminate/support v5.1.2|don't install laravel/framework v5.2.0
>     - don't install illuminate/support v5.1.20|don't install laravel/framework v5.2.0
>     - don't install illuminate/support v5.1.22|don't install laravel/framework v5.2.0
>     - don't install illuminate/support v5.1.25|don't install laravel/framework v5.2.0
>     - don't install illuminate/support v5.1.28|don't install laravel/framework v5.2.0
>     - don't install illuminate/support v5.1.30|don't install laravel/framework v5.2.0
>     - don't install illuminate/support v5.1.31|don't install laravel/framework v5.2.0
>     - don't install illuminate/support v5.1.41|don't install laravel/framework v5.2.0
>     - don't install illuminate/support v5.1.6|don't install laravel/framework v5.2.0
>     - don't install illuminate/support v5.1.8|don't install laravel/framework v5.2.0
>     - Installation request for laravel/framework 5.2.* -> satisfiable by laravel/framework[5.2.41, v5.2.0, v5.2.1, v5.2.10, v5.2.11,
> v5.2.12, v5.2.13, v5.2.14, v5.2.15, v5.2.16, v5.2.17, v5.2.18,
> v5.2.19, v5.2.2, v5.2.20, v5.2.21, v5.2.22, v5.2.23, v5.2.24, v5.2.25,
> v5.2.26, v5.2.27, v5.2.28, v5.2.29, v5.2.3, v5.2.30, v5.2.31, v5.2.32,
> v5.2.33, v5.2.34, v5.2.35, v5.2.36, v5.2.37, v5.2.38, v5.2.39, v5.2.4,
> v5.2.40, v5.2.42, v5.2.43, v5.2.44, v5.2.45, v5.2.5, v5.2.6, v5.2.7,
> v5.2.8, v5.2.9].
>     - Installation request for witty/laravel-push-notification dev-master -> satisfiable by
> witty/laravel-push-notification[dev-master].

Answer 1

库witty/laravel-push-notification太老了，无法在5.2版中安装Laravel。laravel-push-notification的依赖项之一是版本"5.0.* | 5.1.*"中的illuminate/support。

您正在尝试安装Laravel5.2，但该库需要Laravel5.1才能工作。

下一次也尽量不要删除composer.lock，有时它可以保存项目。