Turing tar-pit

Turing tar-pit n.  1. A place where anything is possible but
   nothing of interest is practical.  Alan Turing helped lay the
   foundations of computer science by showing that all machines and
   languages capable of expressing a certain very primitive set of
   operations are logically equivalent in the kinds of computations
   they can carry out, and in principle have capabilities that differ
   only in speed from those of the most powerful and elegantly
   designed computers.  However, no machine or language exactly
   matching Turing's primitive set has ever been built (other than
   possibly as a classroom exercise), because it would be horribly
   slow and far too painful to use.  A `Turing tar-pit' is any
   computer language or other tool that shares this property.  That
   is, it's theoretically universal -- but in practice, the harder
   you struggle to get any real work done, the deeper its inadequacies
   suck you in.  Compare {bondage-and-discipline language}.  2. The
   perennial {holy wars} over whether language A or B is the "most
   powerful".