Mac High Sierra下用Homebrew安装PHP5.6的mcrypt扩展失败求助

Hey there, I’ve run into this exact problem before—those old Homebrew formulas for PHP 5.x extensions got retired back in 2018, so the php56-mcrypt command won’t work anymore. Let me walk you through the current, reliable way to get mcrypt up and running with PHP 5.6:

Step 1: Install PHP 5.6 via a Third-Party Tap #

Since Homebrew’s core repo no longer supports old PHP versions, use the maintained third-party tap for legacy PHP builds:

• Add the tap first:

  brew tap shivammathur/php
  

• Install PHP 5.6:

  brew install shivammathur/php/php@5.6
  

• Link it to make it your active PHP version (you might need to unlink other PHP versions first with brew unlink php if needed):

  brew link php@5.6 --force
  

Step 2: Install mcrypt via PECL #

With PHP 5.6 set up, we’ll use PECL (the PHP Extension Community Library) to install the mcrypt extension:

• First, install the mcrypt system dependency:

  brew install mcrypt
  

• Install the compatible mcrypt version for PHP 5.6 (version 1.0.1 is the last one that supports PHP 5.x):

  pecl install mcrypt-1.0.1
  

  When prompted for the mcrypt prefix, just hit enter—it should auto-detect the path from Homebrew.

Step 3: Enable the Extension in php.ini #

• Locate your PHP 5.6 php.ini file (typically at /usr/local/etc/php/5.6/php.ini).
• Open it in a text editor and add this line at the end:

  extension=mcrypt.so
  

• Restart your PHP service (e.g., if using php-fpm, run brew services restart php@5.6; if using Apache, restart Apache).

Step 4: Verify the Installation #

Run this command to check if mcrypt is loaded:

php -m | grep mcrypt

If you see mcrypt printed out, you’re all set!

Why the Old Method Stopped Working #

Back in March 2018, Homebrew deprecated and removed the dedicated PHP tap, which included all the old PHP version formulas and their companion extensions like php56-mcrypt. Legacy PHP support moved to community-maintained taps like the one we used here, and extensions are now installed via PECL instead of dedicated brew formulas.

内容的提问来源于stack exchange，提问作者Jose Rojas