How can I set PHP 7.2 under Debian 10?

Question

I'm trying to install phpBB and am getting that PHP 7.3 is too new to be supported, with a suggestion of downgrading to 7.2.

Am I correct that I want to downgrade PHP to 7.2, and if so, what are the preferred methods? aptitude does not appear to offer a php7.2 complement of functions.

I might be able to install from source, but if that's the best option I see, I probably don't see the best option.

How can / should I make PHP 7.2 available to phpBB, whether through making a parallel PHP 7 installation or some other means?

--UPDATE--

Managing Multiple Versions ends:

sudo update-alternatives --set php /usr/bin/php7.0
sudo update-alternatives --set php-config /usr/bin/php-config7.0
sudo update-alternatives --set phpdbg /usr/bin/phpdbg7.0
sudo update-alternatives --set phpize /usr/bin/phpize7.0

All but the first one return a result like update-alternatives: error: no alternatives for phpize. Is this a problem?

Also, for me having multiple PHP versions available is a want and not a need. A single recent, lingua franca release would be welcome.

As far as Apache integration goes, is anything more needed to get PHP to pull e.g. 7.2 after having set it up running a2enmod php7.4?

Thanks,

Answer 1

Googling PHP 7.2 on Debian 10 gives several tutorials, but it's not recommended to just follow the first one you can find i.e. Don't blindly follow bad advice. Currently it's DEB.SURY.ORG that is providing fresh PHP packages for Debian, with multiple different PHP versions.

1. The README.txt has a script for adding the repository to Debian.
2. Managing Multiple Versions seems to be made Ubuntu in mind, but should work on Debian, too.
3. Because you wish to use PHP 7.2 only with the phpBB, and PHP 7.3 or 7.4 with other sites, I'd recommend adding PHP-FPM pools for each site (a short example). This way you can not only use multiple PHP versions, but also run the scripts as different users, further securing your configuration.