因為版本過低而導(dǎo)致composer服務(wù)器安裝擴展失敗怎么呢？下面由composer教程欄目給大家介紹其升級過程！

ps : 服務(wù)器 配置

Linux VM-0-9-ubuntu 4.4.0-91-generic #114-Ubuntu SMP Tue Aug 8 11:56:56 UTC 2017 x86_64 x86_64 x86_64 GNU/Linux

1. 失敗經(jīng)歷

安裝 easyswoole 的過程中，發(fā)現(xiàn)無法通過 composer 安裝

報錯信息如下：

ubuntu@VM-0-9-ubuntu:~/demo/easyswoole$ composer require easyswoole/easyswoole=3.x ./composer.json has been created Loading composer repositories with package information Updating dependencies (including require-dev) Installation failed, deleting ./composer.json.                                                                                               [ErrorException]                                                                            "continue" targeting switch is equivalent to "break". Did you mean to use "continue 2"?                                                                                               require [--dev] [--prefer-source] [--prefer-dist] [--no-plugins] [--no-progress] [--no-update] [--update-no-dev] [--update-with-dependencies] [--ignore-platform-reqs] [--sort-packages] [-o|--optimize-autoloader] [-a|--classmap-authoritative] [--] [<packages>]..

google 一下，沒有對應(yīng)的錯誤信息。 想著先查看一下 composer 版本

發(fā)現(xiàn) ： composer 版本過低，就順便升級composer 升級了再說。

ubuntu@VM-0-9-ubuntu:~/demo/easyswoole$ composer -V Composer version @package_branch_alias_version@ (1.0.0-beta2) 2016-03-27 16:00:34

升級的過程中發(fā)現(xiàn)，升級失敗。 老版本的 composer 不能自動升級

ubuntu@VM-0-9-ubuntu:~$ composer self-update                                             [InvalidArgumentException]                Command "self-update" is not defined.

看來是 composer 包太低，都沒有自動升級的功能

2. 下載新的 composer 包

1. 新增最新的composer

wget https://dl.laravel-china.org/composer.phar -O /usr/local/bin/composer  sudo chmod a+x /usr/local/bin/composer

然后把腳本 覆蓋到原來的 （通過軟鏈）

2. 查看原來的位置

sudo mv /usr/bin/composer /tmp/  sudo ln -s /usr/local/bin/composer  /usr/bin/composer  ubuntu@VM-0-9-ubuntu:~$ composer -V Composer version 1.8.5 2019-04-09 17:46:47

3. 安裝

使用 composer 安裝項目