In my earlier comment about this being a workable solution (#808 (comment)), I forgot about the fundamental issue with the composer dependency requirements.

If there were an equivalent of the commandline --ignore-platform-reqs=laravel/serializable-closure that could be baked into composer.json, that would solve the problem, but I don't think such a thing exists. There is the platform option, which could fake a specific version of PHP for dependency resolution, but that seems like a dangerous hack because it applies to all dependencies (not just laravel/serializable-closure).

Sadly, I'm all out of ideas here.

Maybe we can put laravel/serializable-closure in the suggest field and use it if it's installed?

Something like:

{
    "suggest": {
        "laravel/serializable-closure": "Allows a closure interface that isn't deprecated in PHP 8.1+"
    }
}

if (class_exists('Laravel\SerializableClosure\SerializableClosure')) {
    # use laravel/serializable-closure
} else {
    # use opis/closure
}

@hemberger I like that solution as a minor release solution.

@mnapoli I understand that you probably don't want to rush a major version, but this seems like a very good time to drop support for unsupported PHP versions.

🤦 I completely forgot about PHP 7.2 and the Composer requirement.

Yeah… I think we'll need to jump to PHP 7.3. We won't need a major release though.

Yep pretty stupid - PHP7 is old news, now need to deal with this problem causing a MC system to fail.