From The KnpU Comments (https://knpuniversity.com/screencast/symfony2-ep1#comment-1168737351)

Hi again,

In your chapter "Fixtures and External Libraries", apparently, now this command:
php composer.phar update doctrine-fixtures-bundle

We have this message:
Package "doctrine-fixtures-bundle" listed for update is not installed. Ignoring.

We need to write the complete name of package:
php composer.phar update doctrine/doctrine-fixtures-bundle

(http://getcomposer.org/doc/03-cli.md#update)

This fuzzy-matching syntax used to work, but I think it may have just been a bug and I don't think it works now.