Available versions incorrectly set

Migrated issue

Reported by: DeFr

As far as I can tell, there's a problem with the versions that are considered as available for various projects, at least on the packages.drupal.org/7 endpoint.

Using the following composer.json (stripped down a lot to ease testing) :

{
    "name": "ows/test-composer",
    "description": "Test Composer",
    "type": "project",
    "license": "GPL-2.0+",
    "authors": [
        {
            "name": "",
            "role": ""
        }
    ],
    "repositories": {
        "drupal": {
            "type": "composer",
            "url": "https://packages.drupal.org/7"
        }
    },
    "replace": {
      "drupal/drupal": "7.43"
    },
    "require": {
        "drupal/scald": "1.8",
        "drupal/scald_youtube": "1.5"
    },
    "require-dev": {
        "drupal/devel": "1.0",
        "drupal/stage_file_proxy": "1.7"
    },
    "minimum-stability": "dev",
    "prefer-stable": true
}

And running a simple composer install, composer response is

Your requirements could not be resolved to an installable set of packages.
Problem 1
- The requested package drupal/scald_youtube 1.5 exists as drupal/scald_youtube[1.3.0, 1.1.0, 1.0.0, 1.0.0-rc3, 1.0.0-rc2, 1.0.0-rc1, 1.0.0-beta4, 1.0.0-beta3, 1.0.0-beta2, 1.0.0-beta1] but these are rejected by your constraint.
Problem 2
- The requested package drupal/devel 1.0 exists as drupal/devel[dev-5.0.x, 5.0.x-dev, dev-4.0.x, 4.0.x-dev, dev-3.0.x, 3.0.x-dev, dev-2.0.x, 2.0.x-dev] but these are rejected by your constraint.

That doesn't match the respective package releases on d.o, so that's a bit problematic.

For Scald Youtube, I think the problem is partly coming from the fact that the module used to be part of Scald, and was spun off into a separate submodule for the 7.x-1.4 release ; the releases would then match the various releases were Scald Youtube was part of Scald. Not sure how to handle that from a composer point of view though.

For devel, I've no idea were the available versions are coming from, but it's clearly not what I would expect looking at the devel git repository.