【扩展】
必要扩展：
OpenSSL PHP Extension
PDO PHP Extension
Mbstring PHP Extension
Tokenizer PHP Extension
XML PHP Extension
Ctype PHP Extension
JSON PHP Extension
BCMath PHP Extension
查看系统 PHP 已安装的扩展：
php -m
输出：
[PHP Modules] bcmath Core ctype curl date dom filter ftp gd hash iconv imap intl ionCube Loader json libxml mbstring mysqli mysqlnd openssl pcre PDO pdo_mysql pdo_sqlite Phar posix readline Reflection session SimpleXML soap sockets SPL sqlite3 standard tokenizer xml xmlreader xmlrpc xmlwriter xsl Zend OPcache zip zlib [Zend Modules] Zend OPcache the ionCube PHP Loader + ionCube24
【排错】
报错：production.ERROR: PHP Fileinfo extension must be installed/enabled to use Intervention Image.
表现为网页报错 500 。查看日志，发现需要PHP扩展：Fileinfo
日志：/storage/logs/laravel-2019-11-13.log