PHP 7.3 on Ubuntu 18

Given the recent announcement that php 7.3 will be the lowest supported version as of Nov 2020, I tried to update my ubuntu 18 development server from 7.2 to either 7.3 or 7.4. I tried both, and am having issues with php-memcached.

It seems the preferred way to update U18 to 7.3 or above is to use packages from the ppa:ondrej/php repo. After updating to either 7.3 or 7.4 and reinstalling all required packages for the new version, I am receiving this error any time I run validate.php, daily.php, or any other PHP code:

PHP Warning:  PHP Startup: Unable to load dynamic library '' (tried: /usr/lib/php/20180731/ (/usr/lib/php/20180731/ undefined symbol: igbinary_serialize), /usr/lib/php/20180731/ (/usr/lib/php/20180731/ cannot open shared object file: No such file or directory)) in Unknown on line 0

Any one else facing the same issues?

nevermind, uninstalling all php 7.2 packages fixed this