Php 问题1-结论：don'；t安装zendframework/zend缓存

我正在创建一个项目

 php composer.phar create-project -sdev zendframework/skeleton-application zf3-helloworld 
 cd zf3-helloworld/
 cp composer.phar zf3-helloworld/
 cd zf3-helloworld/

 php composer.phar update

我正在使用PHP7.2

我安装了几个没有问题的软件包，但是尝试安装软件包zendframework/zend cache时，会出现以下错误：

Using version ^2.8 for zendframework/zend-cache
./composer.json has been updated
Loading composer repositories with package information
Updating dependencies (including require-dev)
Your requirements could not be resolved to an installable set of packages.

  Problem 1
    - Conclusion: don't install zendframework/zend-cache 2.8.2
    - Conclusion: don't install zendframework/zend-cache 2.8.1
    - Conclusion: don't install zendframework/zend-cache 2.8.0
    - Conclusion: don't install zendframework/zend-cache 2.9.x-dev
    - Conclusion: remove zendframework/zend-eventmanager 3.1.0
    - Installation request for zendframework/zend-cache ^2.8 -> satisfiable by zendframework/zend-cache[2.8.0, 2.8.1, 2.8.2, 2.9.x-dev, 2.8.x-dev].
    - Conclusion: don't install zendframework/zend-eventmanager 3.1.0
    - zendframework/zend-cache 2.8.x-dev requires zendframework/zend-eventmanager ^2.6.3 || ^3.2 -> satisfiable by zendframework/zend-eventmanager[2.6.3, 2.6.4, 3.2.0, 3.2.1, 3.3.x-dev, 3.2.x-dev, 2.6.x-dev].
    - Can only install one of: zendframework/zend-eventmanager[2.6.3, 3.1.0].
    - Can only install one of: zendframework/zend-eventmanager[2.6.4, 3.1.0].
    - Can only install one of: zendframework/zend-eventmanager[3.2.0, 3.1.0].
    - Can only install one of: zendframework/zend-eventmanager[3.2.1, 3.1.0].
    - Can only install one of: zendframework/zend-eventmanager[3.3.x-dev, 3.1.0].
    - Can only install one of: zendframework/zend-eventmanager[3.2.x-dev, 3.1.0].
    - Can only install one of: zendframework/zend-eventmanager[2.6.x-dev, 3.1.0].
    - Installation request for zendframework/zend-eventmanager (locked at 3.1.0) -> satisfiable by zendframework/zend-eventmanager[3.1.0].


Installation failed, reverting ./composer.json to its original content.

我将本教程用作基础：

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通常，发生这种情况的原因是软件包版本冲突

我建议重新启动安装过程，因为您的项目是新的，我认为这比解决所有冲突更快

首先，清除已安装的缓存和数据：

rm -rf composer.lock vendor
php composer.phar clear

重新安装有冲突问题的包

php composer.phar require zendframework/zend-session

安装其他软件包后。例如：

php composer.phar require zendframework/zend-cache
php composer.phar require zendframework/zend-mvc
php composer.phar require zendframework/zend-db
php composer.phar require zendframework/zend-modulemanager
php composer.phar require zendframework/zend-mvc
php composer.phar require zendframework/zend-mvc-i18n
php composer.phar require zendframework/zend-crypt
php composer.phar require zendframework/zend-escaper
php composer.phar require zendframework/zend-mail
php composer.phar require zendframework/zend-paginator

在下面的教程中，也就是说，我认为标记为Y的开关代替了N，这是对最小安装包的回答

   Do you want a minimal install (no optional packages)? Y/n
n

但是，清除所有解决问题的数据