On 2014-04-10 at 06:00:43 +0200, Vivian McPhail wrote:
> Indeed.
>
> It was using the wrong cabal-install version.  Even though I had installed
> the newest cabal-install I needed to restart the xterm I was working
> in.

Lemme guess, you're using Bash, and you installed cabal-install into a
new location; however Bash caches the paths of called executables, see also

 http://unix.stackexchange.com/questions/5609/how-do-i-clear-bashs-cache-of-paths-to-executables