Crock

 CROCK [probably from "layman" slang, which in turn may be
       derived from "crock of shit"] n. An awkward feature or
       programming technique that ought to be made cleaner. Example: Using
       small integers to represent error codes without the program
       interpreting them to the user is a crock. Also, a technique that works
       acceptably but which is quite prone to failure if disturbed in the
       least, for example depending on the machine opcodes having particular
       bit patterns so that you can use instructions as data words too; a
       tightly woven, almost completely unmodifiable structure.