[[!comment format=mdwn username="joey" subject="""comment 1""" date="2015-05-22T18:13:15Z" content=""" `exceptions` is indeed a new dependency. This is supposed to be handled by Propellor.Bootstrap.checkDepsCommand which is run by --spin. Maybe check if your propellor.cabal includes the `exceptions` dependency, and check if `cabal configure` fails. If it does, it seems like that code would fire, and should install the missing dependency. It worked when I upgraded my systems with it, is all I know. """]]