Doesn't build with either 5

[felixonmars]

Control.Monad.Trans.Either was dropped since either version 5.

[27 of 27] Compiling Main             ( src/Main.hs, dist/build/cgrep/cgrep-tmp/Main.dyn_o )

src/Main.hs:42:1: error:
    Could not find module ‘Control.Monad.Trans.Either’
    Perhaps you meant
      Control.Monad.Trans.Writer (from transformers-0.5.2.0)
      Control.Monad.Trans.Error (from transformers-0.5.2.0)
      Control.Monad.Trans.Reader (from transformers-0.5.2.0)
    Use -v to see a list of the files searched for.
   |
42 | import Control.Monad.Trans.Either
   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

[awgn]

Thanks for reporting. Fixed.