>cabal install darcs ......
Installing library in /home/sw2wolf/.cabal/lib/hashed-storage-0.5.5/ghc-6.10.4
Reading package info from "dist/installed-pkg-config" ... done.
Writing new package config file... done.
cabal: Error: some packages failed to install:
darcs-2.5.1 depends on haskeline-0.6.3.2 which failed to install.
haskeline-0.6.3.2 failed during the configure step. The exception was: