Why PHP >= 7.2 for Gettext v5?

[drzraf]

As per wp-cli/i18n-command#217, WP-Cli i18n-command still use v4 (which does not provide Twig scanner, among others) because it stick to package supporting PHP 5.6. What is itself a consequence of wp-cli requirements regarding WP core which tend to support old version of PHP for a long time.

I wonder why exactly, in October 2019, f6ca83d bumped the mimimum requirements to PHP 7.2? Isn't the codebase/testsuite compatible with PHP 5.6 at all? And if it is, is lowering the min version back to 5.6 feasible?

[oscarotero]

Gettext v5 requires PHP 7.2 because it uses some PHP syntax features not available in older versions:

• scalar type declarations
• return type declarations
• nullable types & void type
• etc

So it's not feasible to back to 5.6 and nether 7.0 (maybe 7.1, but not sure). Anyway, 7.2 is right now an old and unmaintained version, so it's recommended to use, at least 7.3.

I understand the frustration of being stuck to an old version of PHP due WP policies (PHP 5.6 is not supported since more than 2.5 years ago). Maybe wp-cli shouldn't have the same requirements as WP due the end-user is different (I guess wp-cli is for developers). Anyway, it's just my opinion :)