环境：

• osX 10.12.3

• Homebrew 1.1.9

• nginx/1.10.2

• PHP 7.1.1

PHP 7.1.1 (cli) (built: Jan 31 2017 21:43:52) ( NTS DEBUG ) Copyright (c) 1997-2017 The PHP Group Zend Engine v3.1.0, Copyright (c) 1998-2017 Zend Technologies with Xdebug v2.5.0, Copyright (c) 2002-2016, by Derick Rethans

命令行中可以执行：

php -i

检查过php.ini，没有禁止执行的函数（是空的）

disable_functions =

能检测到phpinfo函数，但是不能执行

var_dump(function_exists('phpinfo')); // print true

nginx error log 如下：

*246 upstream prematurely closed connection while reading response header from upstream, client: 127.0.0.1, server: test4.cc, request: "GET /ini.php?a=22e243423 HTTP/1.1", upstream: "fastcgi://127.0.0.1:9000", host: "test4.cc"

请问怎么破？