Typo in .info

You would think so, but because the Fast 404 module's info.yml file is `fast404.info.yml` the dependency is correct.

https://git.drupalcode.org/project/fast_404/-/blob/8.x-2.x/fast404.info.yml

I apologize: I checked the module and noticed the project machine name is fast404, while the module machine name is fast_404.

The error shown from Composer could be not related with the dependencies.

I can confirm I get the same error shown in the issue summary, when I run composer require 'drupal/fast_404_generator:^1.0'.

I cannot say why Composer tries to install drupal/fast404-fast404. Even the composer.json file use the expected package name.

    "require": {
        "php": ">=8.0",
        "drupal/fast_404": "^2.0"
    },

Hmm. that is an issue. I wonder if this is an issue with drupal's package manager... I wonder if there are other examples of this scenario.

It seems strange that composer require 'drupal/fast_404_generator:^1.0' tries to install the drupal/fast404-fast404 package, but composer require drupal/fast_404 install the right package.

I cannot find anything in this project's files that could explain this behavior. If it was an issue on drupal.org side, I would expect the same result when running composer require drupal/fast_404.

I asked on Slackto see if somebody could explain what happens in this case. It is possible to install this module using the following commands.

composer config minimum-stability alpha
composer require 'drupal/fast404:^2.0@alpha' --ignore-platform-reqs
composer require 'drupal/fast_404_generator:^1.0' --ignore-platform-reqs

@apaderno I'm use:
composer require 'drupal/fast_404_generator:^1.0'
and in fast_404_generator.info.yml i see wrong name of dependence:

dependencies:
  - fast_404:fast404

I think, right is drupal:fast_404

drupal:fast_404 would be for a Drupal core module whose machine name is fast_404.

fast_404:fast404 is correct because the project machine name is fast_404 → and the module machine name is fast404.