How to Fix “The requested PHP extension ext-mcrypt * is missing” Error on macOS with PHP Version Mismatch


9 views

When working with PHP on macOS, it's common to encounter version conflicts between the CLI and web server environments. The error message:

The requested PHP extension ext-mcrypt * is missing from your system

typically indicates one of three scenarios:

  • Mcrypt extension isn't properly installed
  • PHP versions differ between CLI and web server
  • Extension isn't enabled in the correct php.ini file

First, let's verify the PHP versions in different environments:

# Check CLI version
php -v

# Check web server version (create a test.php file with phpinfo())

In your case, you're seeing:

  • CLI: PHP 5.4.12
  • Web: PHP 5.3.15

For modern macOS systems, the best approach is using Homebrew:

brew install autoconf
brew install mcrypt
brew install php@5.4 --with-mcrypt

To resolve the version mismatch, we need to ensure both environments use the same PHP installation:

# Link the correct PHP version
brew unlink php
brew link php@5.4 --force

# Update Apache configuration
sudo nano /etc/apache2/httpd.conf
# Ensure this line points to your Homebrew PHP:
LoadModule php5_module /usr/local/opt/php@5.4/libexec/apache2/libphp5.so

After installation, verify mcrypt is properly loaded:

php -i | grep mcrypt
# Should return:
mcrypt support => enabled
mcrypt_filter support => enabled

If Homebrew installation fails, try manual compilation:

wget http://sourceforge.net/projects/mcrypt/files/Libmcrypt/2.5.8/libmcrypt-2.5.8.tar.gz
tar -zxvf libmcrypt-2.5.8.tar.gz
cd libmcrypt-2.5.8
./configure
make
sudo make install

Ensure your php.ini files are consistent:

# Locate all php.ini files
php --ini | grep "Loaded Configuration File"
php -i | grep "Additional .ini files"

Add or uncomment this line in all relevant php.ini files:

extension=mcrypt.so

Many developers encounter the frustrating error The requested PHP extension ext-mcrypt * is missing from your system despite having mcrypt seemingly installed. The root cause typically stems from version mismatches between CLI and web server PHP environments.

First, verify your PHP versions across different environments:

# Check CLI PHP version
php -v

# Check web server PHP version (create phpinfo.php)
<?php phpinfo(); ?>

In your case, the terminal reports PHP 5.4.12 while phpinfo() shows 5.3.15 - this explains why mcrypt appears installed but isn't recognized by Composer.

Method 1: Aligning PHP Versions

Force your system to use the same PHP version everywhere:

# For Homebrew users
brew unlink php && brew link php@5.4 --force

# Update PATH in your shell config
echo 'export PATH="/usr/local/opt/php@5.4/bin:$PATH"' >> ~/.zshrc
echo 'export PATH="/usr/local/opt/php@5.4/sbin:$PATH"' >> ~/.zshrc

Method 2: Installing mcrypt Properly

# For Homebrew PHP installations
brew install mcrypt php54-mcrypt

# Alternative compilation method
wget http://sourceforge.net/projects/mcrypt/files/Libmcrypt/2.5.8/libmcrypt-2.5.8.tar.gz
tar -zxvf libmcrypt-2.5.8.tar.gz
cd libmcrypt-2.5.8
./configure && make && sudo make install

After installation, verify mcrypt appears in both environments:

# CLI check
php -m | grep mcrypt

# Web server check
Create a phpinfo.php file containing:
<?php
if (extension_loaded('mcrypt')) {
    echo 'mcrypt is loaded';
} else {
    echo 'mcrypt NOT loaded';
}
?>

If the issue persists only during composer install, try:

composer config -g platform.php 5.4.12
composer install --ignore-platform-reqs