Force composer to download git repo instead of zip

The quickest solution is to run install or update with the option --prefer-source

php composer.phar install --prefer-source

In this way git clone will be used for all dependencies, I don't know if there's a setting to limit to one dependency only.

As explained in preferred-install order matters. I've tested on Composer version 1.8.3 2019-01-30 08:31:33

"config": {
    "preferred-install": {
        "drupal/external_entities": "source",
        "*": "dist"
    }
}

Next ran

composer require drupal/external_entities

and the git repo appeared.

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