Unable to guess the mime type as no guessers are available (Did you enable the php_fileinfo extension?)

上传图片报如下错误：

Unable to guess the mime type as no guessers are available (Did you enable the php_fileinfo extension?)

主要原因是 php_fileinfo 未被开启。

解决

找到 php.ini

$  php -i | grep php.ini
Configuration File (php.ini) Path => /usr/local/php/etc
Loaded Configuration File => /usr/local/php/etc/php.ini

开启 php_fileinfo

$ vim /usr/local/php/etc/php.ini 

找到：;extension=php_fileinfo.dll 去掉分号，
windows 是 dll 但如果是 linux 系统的话应该是
extension=php_fileinfo.so