Laravel 5 "；https://packagist.org/packages.json" 无法下载文件

我想为我正在制作的Laravel聊天应用程序安装一个软件包。运行“composer require foo/bar”时，终端中出现以下错误：

In RemoteFilesystem.php line 515:

The "https://packagist.org/packages.json" file could not be downloaded: failed to open stream: Unable to find the socket transport "proxy_user_name" - did you forget to enable it when you configured PHP?

我正在使用VPN，但它仍然引用我的代理凭据，因为VPN，该凭据不应该被看到

运行“composer diagnose”时，我得到以下信息：

Lolo@lolo:/media/lolo/project_path/project_name$ 
composer diagnose
Checking composer.json: OK
Checking platform settings: OK
Checking git settings: OK
Checking http connectivity to packagist: WARNING

[Composer\Downloader\TransportException] The "http://packagist.org/packages.json" file could not be downloaded: failed to open stream: Unable to find the socket transport "foobar" - did you forget to enable it when you configured PHP?

Checking https connectivity to packagist: WARNING
[Composer\Downloader\TransportException] The "https://packagist.org/packages.json" file could not be downloaded: failed to open stream: Unable to find the socket transport "foobar" - did you forget to enable it when you configured PHP?

Checking HTTP proxy: FAIL
[Composer\Downloader\TransportException] The "https://packagist.org/packages.json" file could not be downloaded: failed to open stream: Unable to find the socket transport "foobar" - did you forget to enable it when you configured PHP?

Checking HTTP proxy support for request_fulluri: WARNING
Unable to assess the situation, maybe packagist.org is down (The "http://packagist.org/packages.json" file could not be downloaded: failed to open stream: Unable to find the socket transport "foobar" - did you forget to enable it when you configured PHP?)

Checking HTTPS proxy support for request_fulluri: WARNING

Unable to assess the situation, maybe github is down (The "https://api.github.com/repos/Seldaek/jsonlint/zipball/1.0.0" file could not be downloaded: failed to open stream: Unable to find the socket transport "foobar" - did you forget to enable it when you configured PHP?)
Checking github.com rate limit: FAIL

[Composer\Downloader\TransportException] The "https://api.github.com/rate_limit" file could not be downloaded: failed to open stream: Unable to find the socket transport "foobar" - did you forget to enable it when you configured PHP?

Checking disk free space: OK
Composer version: 1.6.3
PHP version: 7.2.7-0ubuntu0.18.04.2
PHP binary path: /usr/bin/php7.2

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什么可能导致错误？

这是由于代理配置不正确造成的。请尝试更正您的代理或使用（暂时）禁用它

当需要通过代理时，可以使用redsocks

unset http_proxy;
unset https_proxy;