To build, use something similar to:
> docker build -t noteed/ghc-7-4-2 ghc-7-4-2
> docker build -t noteed/ghc-7-6-3 ghc-7-6-3
> docker build -t noteed/ghc-7-8-4 ghc-7-8-4
Typical usage looks like:
> docker run -t -i -v /local/path/to/project:/source noteed/ghc-7-8-4 bash
# /app/halcyon/halcyon install /source