My apologies for any inconvenience. enumerable/each_slice is being
deprecated. Unfortunately the ChangeLog entry for this got mangled
somehow and said nothing but "ice" (the last three letters of of
each_slice). The reason is Ruby now supports each_slice in the standard
library. All you have to do is:

require 'enumerator'

And I beleive as of Ruby 1.9 this will built-in functionality too and
there will no longer be a need for the require (Can anyone verify

Nonetheless I'll am goging to release a minor update to facets today
that fixes this issue. It will be a temproray patch the will just
redirect 'enumerable/each_slice' to 'enumerator'.

One important consideration though is that Ruby's each_slice and
Facets' previous version differ in that Ruby's will not use the block's
arity if no slice count is given --it will raise an Argument error
instead. To get this behavior back use Facets' #each_by (maybe I'll
submit an RCR for this).