I still have 7.8.3 but it doesn't seem to want to build the latest cabal:
ghc --version
The Glorious Glasgow Haskell Compilation System, version 7.8.3
bash-3.2$ cabal install cabal-install
Resolving dependencies...
Configuring cabal-install-1.20.0.6...
Building cabal-install-1.20.0.6...
Installed cabal-install-1.20.0.6
Updating documentation index
/Users/gcolpitts/Library/Haskell/share/doc/index.html
On Thu, Jan 1, 2015 at 2:54 PM, Edward Z. Yang
If you still have your old GHC around, it will be much better to compile the newest cabal-install using the *old GHC*, and then use that copy to bootstrap a copy of the newest cabal-install.
Edward
Excerpts from George Colpitts's message of 2015-01-01 12:08:44 -0500:
$ cabal update Downloading the latest package list from hackage.haskell.org Note: *there is a new version of cabal-install available.* To upgrade, run: cabal install cabal-install bash-3.2$ *cabal install -j3 cabal-install * *...*
*Resolving dependencies...cabal: Could not resolve dependencies:* trying: cabal-install-1.20.0.6 (user goal) trying: base-4.8.0.0/installed-779... (dependency of cabal-install-1.20.0.6) next goal: process (dependency of cabal-install-1.20.0.6) rejecting: process-1.2.1.0/installed-2db... (conflict: unix==2.7.1.0, process => unix==2.7.1.0/installed-4ae...) trying: process-1.2.1.0 next goal: directory (dependency of cabal-install-1.20.0.6) rejecting: directory-1.2.1.1/installed-b08... (conflict: directory => time==1.5.0.1/installed-c23..., cabal-install => time>=1.1 && <1.5) rejecting: directory-1.2.1.0 (conflict: base==4.8.0.0/installed-779..., directory => base>=4.5 && <4.8) rejecting: directory-1.2.0.1, 1.2.0.0 (conflict: base==4.8.0.0/installed-779..., directory => base>=4.2 && <4.7) rejecting: directory-1.1.0.2 (conflict: base==4.8.0.0/installed-779..., directory => base>=4.2 && <4.6) rejecting: directory-1.1.0.1 (conflict: base==4.8.0.0/installed-779..., directory => base>=4.2 && <4.5) rejecting: directory-1.1.0.0 (conflict: base==4.8.0.0/installed-779..., directory => base>=4.2 && <4.4) rejecting: directory-1.0.1.2, 1.0.1.1, 1.0.1.0, 1.0.0.3, 1.0.0.0 (conflict: process => directory>=1.1 && <1.3) Dependency tree exhaustively searched.