Root composer.json requires magento/composer-root-update-plugin

[digitalstartup]

I’ve heard some instances of Magento 2.4.x installation failures, that kick out the following error:

Your requirements could not be resolved to an installable set of packages.

Problem 1
  - Root composer.json requires magento/composer-root-update-plugin ~1.0 -> satisfiable by magento/composer-root-update-plugin[1.0.0].
  - magento/composer-root-update-plugin 1.0.0 requires composer-plugin-api ^1.0 -> found composer-plugin-api[2.0.0] but it does not match the constraint.
Problem 2
  - Root composer.json requires dealerdirect/phpcodesniffer-composer-installer ^0.5.0 -> satisfiable by dealerdirect/phpcodesniffer-composer-installer[v0.5.0].
  - dealerdirect/phpcodesniffer-composer-installer v0.5.0 requires composer-plugin-api ^1.0 -> found composer-plugin-api[2.0.0] but it does not match the constraint.
Problem 3
  - laminas/laminas-dependency-plugin[1.0.0, ..., 1.0.4] require composer-plugin-api ^1.1 -> found composer-plugin-api[2.0.0] but it does not match the constraint.
  - magento/product-community-edition 2.4.0 requires laminas/laminas-dependency-plugin ^1.0 -> satisfiable by laminas/laminas-dependency-plugin[1.0.0, ..., 1.0.4].
  - Root composer.json requires magento/product-community-edition 2.4.0 -> satisfiable by magento/product-community-edition[2.4.0].

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.

[digitalstartup]

I’m lead to believe that this is due to an incompatibility with Composer 2.x. So, if you already have Composer installed, you can try to downgrade your copy to the latest 1.x version using the following command:

composer self-update 1.10.16

I don’t think this needs to be run as a “superuser”. But if you do have trouble then run the command as a “superuser” and prefix it with “sudo”.

At this point your should be able to continue where you left off.