I had a specific use-case that ensures a property while using a Consul session via the consul-haskell package; in order to make it type check a MonadBaseControl IO instance is needed, so I added one. Hopefully this is generally useful, so I don't need to maintain a forked version of propellor!

Patch is located in the MonadBaseControl branch of my cloned git repo git clone git@github.com:hellertime/propellor.git