Composer custom package error : Skipped branch develop, Undefined index: name

I am trying to load a small package I made from a remote git repository but i'm still getting the same error whatever I do.

Here is the code of the local composer I am running :

    {
    "require": {
        "kdyby/fake-session": "^2.0",
        "monolog/monolog": "^1.19",
    },

    "repositories": [
        {
            "type": "git",
            "url": "http://xxxx/master/Core.git" }
    ],

    "config": 
        {
            "secure-http": false
        }
    }

And this is the remote composer.json :

    {
    "repositories": [
        {
            "type": "package",
            "package": {
                "name": "master/core",
                "version": "dev-master",
                "source": {
                    "url": "http://xxxx/master/Core.git",
                    "type": "git",
                    "reference": "origin/develop"
                }
            }
        }
    ],
    "require": {
        "master/core": "dev-master"
        }
    }

Here are the logs from my console :

$ composer require master/Core Reading composer.json of http://xxxx/master/Core.git (develop) Skipped branch develop, Undefined index: name

[Composer\Repository\InvalidRepositoryException] No valid composer.json was found in any branch or tag of http://xxxx/master/Core.git, could not load a package from it.

Note that I am trying to get the files from the develop branch and I guess it's reaching the composer.json since it's saying there is an error.

The owner of the repository is "master", that's why there is a master/core, nothing to do here with the master branch.

I've found many issues about undefined index version, but didn't find a working fix for the undefined index name. I tried many version of the remote composer file with examples/fixes from the internet, but none worked.

There must be an obvious issue in my files, or something i don't get about composer. Thanks for any help.

Edit : solved my issue, I was wrong on which side having which file.

It's working with local composer.json :

    {
    "repositories": [
        {
            "type": "package",
            "package": {
                "name": "master/core",
                "version": "dev",
                "source": {
                    "url": "http://xxxx/master/Core.git",
                    "type": "git",
                    "reference": "develop"
                }
            }
        }
    ],
    "require": {
        "master/core": "dev"
        }
    }

and remote composer.json :

    {
       "name": "master/Core"
    }

Note : You must have the composer.json gitted even if working with local files for both (local and remote) or it will not work if you use a "type":"git".

You have to create composer.json file

and it should have at least those information:

{
    "name": "your-vendor-name/package-name",
    "description": "A short description of what your package does"
}

Reference: https://packagist.org/