composer 安装 fecmall 报错

以下是报错信息:

The archive may contain identical file names with different capitalization (which fails on case insensitive filesystems)

Unzip with unzip command failed, falling back to ZipArchive class

• Installing psr/http-message (1.0.1): Downloading (failed)
  Downloading (failed)
  Downloading (failed) Failed to download psr/http-message from dist: The "https://api.github.com/repos/php-fig/http-message/zipball/f6561bf28d520154e4b0ec72be95418abe6d9363" file could not be downloaded: failed to open stream: Connection refused Now trying to download from source
• Installing psr/http-message (1.0.1):

[Symfony\Component\Process\Exception\RuntimeException]
The Process class relies on proc_open, which is not available on your PHP installation.