This is a PHP 5.6 compatibility hotfix for yesterday's 2.2.2 release. There were no code changes other than regenerating the Composer autoload files on PHP 5.6 (see built diff). There was a syntax error being caused in PHP 5.6 due to Composer generating syntax that requires PHP 7+. See https://github.com/ampproject/amp-wp/pull/7030.

👉 Note: The next AMP plugin version will likely increase the minimum PHP version to 7 since only 6.6% of WordPress installs are currently on PHP 5.6, which is also a legacy PHP version that is no longer maintained and is much slower than PHP 7 (or PHP 8).

Installation

Now available to install via WordPress.org.

You can also install the amp.zip build linked below by uploading it in the WordPress admin.

To install as a Git submodule, consider 2.2.3-built.