Magento-lts: Incompatibility with composer 2.0

[astyczen]

Preconditions (*)

1. OpenMage version 19.4.7
2. Composer version 1.10.13 2020-09-09 11:46:34
3. PHP version 7.3.18

Steps to reproduce (*)

1. Update composer file for installation
   "require": {
   "aydin-hassan/magento-core-composer-installer": "*",
   "openmage/magento-lts": "19.4.7"
   },
   "extra": {
   "magento-core-package-type": "magento-source",
   "magento-root-dir": "."
   }
2. Run: composer install

Expected result (*)

1. Installation passes and all needed packages get installed properly.

Actual result (*)

1. Composer error during installation connected to composer-plugin-api not existing in version ~1.0 any more. Main problem is with aydin-hassan/magento-core-composer-installer and magento-hackathon/magento-composer-installer requiring non existant package.
   _Problem 1
   
   
   
   • Root composer.json requires aydin-hassan/magento-core-composer-installer 1.5.0 -> satisfiable by aydin-hassan/magento-core-composer-installer[1.5.0].
   
   
   • aydin-hassan/magento-core-composer-installer 1.5.0 requires composer-plugin-api ~1.0 -> found composer-plugin-api[2.0.0] but it does not match the constraint.
     
     Problem 2
   
   
   • magento-hackathon/magento-composer-installer[3.1.0, ..., 3.2.3] require composer-plugin-api ^1.0 -> found composer-plugin-api[2.0.0] but it does not match the constraint.
   
   
   • magento-hackathon/magento-composer-installer 2.1.3 requires composer-plugin-api ~1.0 -> found composer-plugin-api[2.0.0] but it does not match the constraint.
   
   
   • magento-hackathon/magento-composer-installer[2.1.0, ..., 2.1.1] require composer-plugin-api 1.0.0 -> found composer-plugin-api[2.0.0] but it does not match the constraint.
   
   
   • openmage/magento-lts v19.4.7 requires magento-hackathon/magento-composer-installer ^3.1 || ^2.1 -> satisfiable by magento-hackathon/magento-composer-installer[2.1.0, 2.1.1, 2.1.3, 3.1.0, ..., 3.2.3].
   
   
   • Root composer.json requires openmage/magento-lts 19.4.7 -> satisfiable by openmage/magento-lts[v19.4.7].
     
     You are using Composer 2, which some of your plugins seem to be incompatible with. Make sure you update your plugins or report a plugin-issue to ask them to support Composer 2._
   
   

[Flyingmana]

Related to https://github.com/Cotya/magento-composer-installer/issues/191
And Related to https://github.com/AydinHassan/magento-core-composer-installer/issues/50

[Flyingmana]

This is solved in the latest release of both installers
(tested with https://github.com/Cotya/OpenMage-demo-deployment/blob/9e61a1eb6b88571a8a0309a05d740c04c53573de/src/composer.json#L6 )

as OpenMage has a stricter limit on compatible installer versions (we should be more open here maybe), this will only work from the next OpenMage release on.
Till then you need to add a small workaround by requiring the installer as a different version

"magento-hackathon/magento-composer-installer": "4.0.1 as 3.2.3",

[Vinai]

Is this issue now solved since release 20.0.5?
The composer.json includes 4.0.1 as far as I can tell.

"magento-hackathon/magento-composer-installer": "^3.1 || ^2.1 || ^4.0"

[Flyingmana]

Yes, thank you for reminding us to close this Issue :)

In case you (or anyone else) notices any Issues with Composer 2.0, please feel free to inform us