I tried to update git-annex via cabal. It fails due to lens not installing:
juh@sokrates:~$ cabal update Downloading the latest package list from hackage.haskell.org juh@sokrates:~$ cabal install git-annex Resolving dependencies... In order, the following will be installed: lens-4.2 (new version) DAV-0.6.2 (reinstall) changes: http-client-0.3.1.1 -> 0.3.3.1, http-client-tls-0.2.1.1 added, http-types-0.8.4 -> 0.8.5, lens-4.1.2 -> 4.2, network-184.108.40.206 added, optparse-applicative-0.7.0.2 added, xml- conduit-220.127.116.11 -> 18.104.22.168, xml-hamlet-0.4.0.8 added git-annex-5.20140707 (new package) Warning: Note that reinstalls are always dangerous. Continuing anyway... [1 of 1] Compiling Main ( /tmp/lens-4.2-3107/lens-4.2/Setup. lhs, /tmp/lens-4.2-3107/lens-4.2/dist/setup/Main.o ) Linking /tmp/lens-4.2-3107/lens-4.2/dist/setup/setup ... Configuring lens-4.2... Building lens-4.2... Preprocessing library lens-4.2... src/Control/Lens/Internal/Zoom.hs:47:8: Could not find module `Control.Monad.Trans.Except' Perhaps you meant Control.Monad.Trans.Cont (from transformers-0.3.0.0) Control.Monad.Trans.Error (from transformers-0.3.0.0) Control.Monad.Trans.List (from transformers-0.3.0.0) Use -v to see a list of the files searched for. Failed to install lens-4.2 cabal: Error: some packages failed to install: DAV-0.6.2 depends on lens-4.2 which failed to install. git-annex-5.20140707 depends on lens-4.2 which failed to install. lens-4.2 failed during the building phase. The exception was: ExitFailure 1
I am not an experienced user of cabal. So any hints to solve the conflicts are appreciated.