PHP Warning: PHP Startup: Unable to load dynamic library 'mcrypt.so'

Question

I am trying to update laravel using composer update on ubuntu 06.04 but everytime i run composer update this warning always comes up.

PHP Warnin         


        

Answer 1

I faced similar issue when I installed Php7.2 on Ubuntu 18. Though I had installed mcrypt using PECL still I get the error mentioned in the question.

I did following to fix it

sudo apt-get install php-pear php7.2-dev

then uninstalled

pecl uninstall mcrypt

Now reinstall mcrypt

sudo apt-get -y install gcc make autoconf libc-dev pkg-config
sudo apt-get -y install libmcrypt-dev
sudo pecl install mcrypt-1.0.1

When you are shown the prompt

libmcrypt prefix? [autodetect] :

Press [Enter] to autodetect.

After success installing mcrypt using pecl, you should add mcrypt.so extension to php.ini.

The output will look like this:

...
Build process completed successfully
Installing '/usr/lib/php/20170718/mcrypt.so'    ---->   this is our path to mcrypt extension lib
install ok: channel://pecl.php.net/mcrypt-1.0.1
configuration option "php_ini" is not set to php.ini location
You should add "extension=mcrypt.so" to php.ini

Now restart Apache

sudo service apache2 restart

Grab installing path and add to cli and apache2 php.ini configuration.

sudo bash -c "echo extension=/usr/lib/php/20170718/mcrypt.so > /etc/php/7.2/cli/conf.d/mcrypt.ini"
sudo bash -c "echo extension=/usr/lib/php/20170718/mcrypt.so > /etc/php/7.2/apache2/conf.d/mcrypt.ini"