Here is a description of how I installed Montage (https://github.com/bumptech/montage) with GHC 7.6.1
First clone these repos (the relevant commit I used is listed below each clone command)
mkdir montage_depscd montage_depsgit clone git clone git@github.com:wmoss/StatsWeb.gitcd StatsWebgit checkout d65376e37b315897226e37946faa35e1b1a328f5cabal installcd ..git clone https://github.com/bumptech/riak-haskell-client.gitcd riak-haskell-clientgit checkout 1a773db41681c895021206a742f889a20daf5875cd protobuf && cabal installcd .. && cabal installcd ..git clone https://github.com/bumptech/pool.gitcd poolgit checkout b72a259dc375cce4a8208eedc58d8252b3c44201cd ..
Next I installed some C dependencies using homebrew (http://brew.sh/):
brew install libev redo libsodium
Grab the nitro C code from http://gonitro.io/ I used v0.2.0
cd folder_with_nitro_coderedosudo redo install
We are now ready to install Montage
cd montage_depsgit clone https://github.com/bumptech/montage.gitcd montagegit checkout 8ac5d81328b29ddf547673f158a1185b40ceec85cabal install