[wp-trac] [WordPress Trac] #58719: Bump the minimum PHP version to 7.2

[WordPress Trac]

#58719: Bump the minimum PHP version to 7.2
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 Reporter:  justlevine   |       Owner:  johnbillion
     Type:  enhancement  |      Status:  accepted
 Priority:  normal       |   Milestone:  6.6
Component:  General      |     Version:
 Severity:  normal       |  Resolution:
 Keywords:  has-patch    |     Focuses:
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Comment (by jrf):

 Thanks @johnbillion for updating the proposed patch.

 For the record: I fully support upping the minimum supported PHP version
 to PHP 7.2 (or even 7.3) sooner rather than later.

 Keeping WP running PHP cross-version will be getting more and more painful
 if we don't.

 Some examples:

 **SimplePie** has [https://github.com/simplepie/simplepie/pull/743 dropped
 support for PHP < 7.2 in version 1.8.0] which was released in January
 2023.
 WordPress currently cannot update SimplePie anymore, but older SimplePie
 versions will not receive patches to support newer PHP versions, like PHP
 8.3 or PHP 8.4.

 While **Sodium_Compat** (previously discussed as still necessary)
 currently still has a minimum supported PHP version of PHP 5.2.4, I would
 be very surprised if that doesn't get raised to PHP 7.1 in the foreseeable
 future.
 The Sodium_Compat library, in particular, is impacted by the PHP 8.4
 [https://wiki.php.net/rfc/deprecate-implicitly-nullable-types "implicitly
 nullable parameters" deprecation] with 36 instances needing fixing.
 If PHP < 7.1 would continue to be supported, they would need to drop the
 type declarations of the affected function parameters, which is a
 significant BC-break as their classes are not `final`.
 If they'd raise the minimum supported version to 7.1, they can fix these
 issues by using nullable types.
 For ''most'' end-users of Sodium Compat, that wouldn't be a problem as
 those projects use Composer and Composer can sort out that a version is
 installed which is compatible with the server on which the package is
 being run.
 However, WordPress is not one of those users and shipping WP with two
 different versions, while doable, is probably still not the best of ideas.

 **Requests** has already fixed that deprecation, but this means it had to
 make a [https://github.com/WordPress/Requests/releases/tag/v2.0.11
 potential breaking change], though this was (of course) done after careful
 research of uses of the one method for which this BC-break was needed.

 And while the **GetID3** package - for now - still has a minimum of PHP
 5.4 for their 2.0 release, there is
 [https://github.com/JamesHeinrich/getID3/issues/317 a discussion going to
 change this to PHP 7.2] too.

 Aside from the above, **PHP_CodeSniffer** will also have a PHP 7.2 minimum
 as of version 4.0, which is expected sometimes over the next few months.
 This decision was already taken years ago when the 4.0 branch was created
 (2020).
 When **WordPressCS** will be made compatible with PHPCS 4.0, it is likely
 that the minimum supported PHP version for WPCS will need to be raised to
 PHP 7.2 as well, even if PHPCS 3.0 would still be supported.
 As WordPress should always try to enforce the latest version of its own
 coding standards, we cannot allow for an older WPCS version to be
 installed by contributors, which would create an ugly conundrum as WP
 having a dev dependency with a higher minimum PHP version than its own
 minimum PHP version is problematic.

 On top of all that, I've seen some recent patches in WP which introduced
 parameter type declarations. While this is not a great idea in the context
 of WordPress in the first place, though that's beside the point, the
 problem in light of this ticket is that PHP < 7.4 doesn't fully support
 co-variance or contra-variance. And while PHP 7.2 doesn't offer full
 support yet, it is the PHP version in which the first significant steps
 were taken to add support for co-variance and contra-variance to PHP.

 Either way, that's my two pennies. Hope it helps to inform the decision by
 the powers that be.

-- 
Ticket URL: <https://core.trac.wordpress.org/ticket/58719#comment:45>
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