Compatibility with Composer 2.0

[limenet]

Bug Report

A couple days ago, Composer 2.0 was released and for a while now, Composer 1.10.x has been warning about invalid PSR-0 and PSR-4 configurations and most packages have been upgraded/fixed.

From the release post:

Invalid PSR-0 / PSR-4 configurations will not autoload anymore in optimized-autoloader mode, as per the warnings introduced in Composer 1.10.

Further, the release post contains this snippet:

As for Composer 1.x, it is now more or less EOL. It will also receive critical fixes if anything comes up but the goal for everyone should be to migrate to 2.x as soon as possible.

Almost all of Pimcore's dependencies are compatible with Composer 2.0 except for doctrine/doctrine-migrations-bundle which uses an almost two-year old version with now being superseded by two major versions.

Expected behavior

Pimcore can safely be installed with Composer 2.0 which is the new stable version of Composer and replaces Composer 1.x which is now EOL.

Actual behavior

Due to depending on an old version of doctrine/doctrine-migrations-bundle, which is not compatible with Composer 2.0, it is currently not safely possible to use Composer 2.0 when installing Pimcore.

Steps to reproduce

1. Install Composer 1.x
2. Run composer install
3. Observe the following message: Deprecation Notice: Class Doctrine\Bundle\MigrationsBundle\Tests\DependencyInjection\DoctrineCommandTest located in ./vendor/doctrine/doctrine-migrations-bundle/Tests/Command/DoctrineCommandTest.php does not comply with psr-4 autoloading standard. It will not autoload anymore in Composer v2.0. in phar:///usr/local/bin/composer/src/Composer/Autoload/ClassMapGenerator.php:201

I realize this is unlikely to cause any issues (since the message affects a test used by that bundle) yet it unfortunately prevents us from safely using Composer 2.0 in production in conjunction with Pimcore and instead relying on a now EOL version of Composer.

[dpfahlbusch]

There is currently another problem with composer v2.
The wikimedia/composer-merge-plugin is not composer v2 compatible at the moment.

wikimedia/composer-merge-plugin#184

[HaaseIT]

Furthermore, in the pimcore dockerfile:

https://github.com/pimcore/docker/blob/df45b64f4875a5cf1bbeabd91d1d5adc3954dfbb/Dockerfile.template

hirak/prestissimo:^0.3

is required, this is also incompatible with Composer 2.0

[brusch]

Fixed by
#7349
pimcore/skeleton@58516d5
pimcore/demo@116f44e

[HaaseIT]

@brusch What about the the docker part?

[brusch]

@HaaseIT pimcore/docker#29

[limenet]

@brusch thanks for the changes! Most Composer 2.0 issues now appear fixed.

However, while #7349 upgraded a number of Doctrine packages, the one mentioned in my initial report, doctrine/doctrine-migrations-bundle, remained untouched and as such the deprecation notice still appears. I've verified this with the current masters of both the demo and skeleton repo.

Do you have any plans on upgrading that package as well?

[jdreesen]

I don't think that's an issue as it's only a test file that cannot be loaded. You don't want to run the tests locally (when installed as a composer dependency) which is why they are ignored in the export for version 2 & 3.

[brusch]

For 6.x it's fine as it is I'd say (however PRs are welcome), for 7 we're going to update the dependencies anyway.