Using the latest version of Cake released today (v.0.22.0) and referencing MagicChunks in a cake script outputs this error:

Error: The assembly 'MagicChunks.Cake, Version=1.2.0.58, Culture=neutral, PublicKeyToken=null' is referencing an older version of Cake.Core (0.16.2). This assembly need to reference at least Cake.Core version 0.22.0. Another option is to downgrade Cake to an earlier version. It's not recommended, but you can explicitly opt-out of assembly verification by configuring the Skip Verification setting to true (i.e. command line parameter "--settings_skipverification=true", envrionment variable "CAKE_SETTINGS_SKIPVERIFICATION=true", read more about configuration at https://cakebuild.net/docs/fundamentals/configuration)