Can't generate PHP 5.6 compatible autoloader - syntax error, unexpected '(' in autoload_real.php

[khromov]

👋 We have an issue when trying to run composer install on a different PHP version than the target system (local environment uses PHP 8 but prod uses PHP 5.6)

The issue is that autoload_real.php generates this line:

\Composer\Autoload\ComposerStaticInita88cb81bddf628e1783485153a2bdd1f::getInitializer($loader)();

This causes a PHP error:

Parse error: syntax error, unexpected '(' in /var/www/vendor/composer/autoload_real.php on line 32

What we have done is to configure platform in composer.json:

"platform": {
  "php": "5.6"
}

I would then anticipate that a PHP 5.6-compatible autoloader would be generated. At the very least the autoloader code should not depend on the PHP version of the environment that triggers composer install.

This approach used to work up until some time ago, although I don't know at exactly which version it broke.

Output of composer diagnose:

Composer version: 2.3.3
PHP version: 5.6 - Package overridden via config.platform, actual: 8.1.4
PHP binary path: /usr/local/Cellar/php/8.1.4/bin/php

PS. I understand this is a niche problem, we are using a legacy environment and it's quite hard for us to run Composer in PHP 5.6, hence I'm creating this issue.

[stof]

Composer 2.3 requires PHP 7.2.5+, and so will not generate autoloading code compatible with older versions.

If you want the autoloader to be compatible with PHP 5.6, I think you need to stay on the Composer 2.2 LTS.

[khromov]

@stof Thanks so much for quickly pointing me to the right place, following the install guide and picking the 2.2 LTS at the end worked perfectly and generated a valid autoloader for PHP 5.6.

php composer-setup.php --version=2.2.11

[Seldaek]

I took a look and it seems we really can easily support 5.6 still for autoloading purposes, so I fixed that in e0cce2b which will be available in 2.3.4 - hopefully you can then go back to using the latest Composer version :)

[jrfnl]

This is awesome! Thank you so much! (this was actually the underlying reason behind my request the other day for the self-update --2.2 option ;-) )