Given package is missing URL information (null value for dist URL)

Problem/Motivation

It appears the Drupal Composer repository occasionally incorrectly delivers null values as dist URLs which means composer cannot install the respective packages. If these null values end up in lock files it then also makes installation from the lock file impossible until it's either regenerated or the package updated.

Hope this is the right place to report this kind of a bug?

This was fixed for a specific package on someone's request just before Christmas I believe, and another Private Packagist customer ran into this today, so I would appreciate if you could put a general fix in place that prevents your repository from delivering invalid null values as dist URLs.

Steps to reproduce

Create composer.json in empty directory with following contents:

{"repositories": [{"type": "composer", "url": "https://packages.drupal.org/8/packages.json"}]}

Then run composer require drupal/video:1.0 -vvv

It errors with:

In FileDownloader.php line 117:
                                                
  [InvalidArgumentException]                    
  The given package is missing url information  
                                                

Exception trace:
  at phar:///usr/bin/composer/src/Composer/Downloader/FileDownloader.php:117
 Composer\Downloader\FileDownloader->download() at phar:///usr/bin/composer/src/Composer/Downloader/ZipDownloader.php:100
...