title: How to override composer repository source?
body: <p>I'm trying to fork a repo so I can update it with my own code. I've done it before, but something seems to be missing this time.
  When I put the repo path in the composer repository list, it will usually detect that it matches the package and use the package from my repo.
  Here's my composer (simplified for example sake):</p>
  
  <pre><code>{
      "name": "My Project",
      "description": "Project",
      "keywords": ["framework", "laravel"],
      "license": "MIT",
      "repositories" : [
          {
              "url": "https://github.com/phazei/laravel4-datatables-package.git",
              "type": "git"
          },
          {
              "url": "https://github.com/phazei/cashier.git",
              "type": "git"
          }
      ],
      "require": {
          "bllim/datatables": "dev-master-phazei",
          "laravel/cashier": "dev-test"
      },
      "config": {
          "preferred-install": "dist"
      },
      "minimum-stability": "stable"
  }
  </code></pre>
  
  <p>Both requirements are being overridden the exact same way as far as I can tell.  The bllim/datatables reads the "master-phazei" branch from the overridden repository, but cashier seems to entirely ignore it.</p>
  
  <p>If I type <code>composer show bllim/datatables</code> it will list my repo for the source.  But if I type <code>composer show laravel/cashier</code> it shows as if I didn't even have my repo listed.</p>
  
  <p>What could cause this?</p>