laravel/framework — pull request #5518 by MarkRedeman (2014-08-21 19:14:20+00:00)
Title: Removed registering of the tail command.

You forgot to remove the registration of command.tail in the ArtisanServiceProvider after making it an optional component in f62a5f11045ec4e09a5e95e496d6c6c184efe2d9, thus resulting in an error when artisan was called.