The above tarballs should work if you manually constrain the install to use HTTP-4000.2.5 or higher:

  cabal install --constraint="HTTP >= 4000.2.5" http://johantibell.com/files/Cabal-1.20.0-rc.tar.gz http://johantibell.com/files/cabal-install-1.20.0-rc.tar.gz



On Tue, Apr 15, 2014 at 11:07 AM, Johan Tibell <johan.tibell@gmail.com> wrote:
If you run into this error:

Network/HTTP/Auth.hs:192:49:
    Couldn't match expected type `Maybe URI' with actual type `URI'
    In the second argument of `fromMaybe', namely
      `(u `relativeTo` baseURI)'
    In the expression: fromMaybe u (u `relativeTo` baseURI)
    In the first argument of `map', namely
      `(\ u -> fromMaybe u (u `relativeTo` baseURI))'

try using the 1.20 branch on GitHub instead, as I had to work around a missing upper bound on network in the HTTP package. cabal-install only builds reliably with HTTP-4000.2.5 and higher.


On Tue, Apr 15, 2014 at 10:33 AM, Johan Tibell <johan.tibell@gmail.com> wrote:
Hi all,

I've prepared the 1.20 release candidates. I now need some help testing, especially on Windows as I don't have a Windows machine.

To install the release candidates simply run:


Please report any issues on the bug tracker: https://github.com/haskell/cabal/issues

If I haven't heard of anything release blocking bugs (or last minute important patches) in a couple of days, I will make these tarballs the official release.

The commits used are tagged in the repo as Cabal-v1.20.0-rc and cabal-install-v1.20.0-rc.

-- Johan