Have solved the issue with help from JP Moresmau. Used the command cabal install --dry-run --verbose=3 --global build wrapper And this gave enough detailed info to enable me to remove the conflict and resolve the issue. Thanks goes to JP ! On Wednesday, 9 May 2012 at 09:55, Graham Berks wrote:
Given that I have the dependant packages already installed when I do
$ cabal install --dry-run --global buildwrapper Resolving dependencies... In order, the following would be installed: mtl-2.1.1 (new version) aeson-0.6.0.2 (reinstall) changes: mtl-2.0.1.0 -> 2.1.1 parsec-3.1.2 (reinstall) changes: mtl-2.0.1.0 -> 2.1.1 regex-base-0.93.2 (reinstall) changes: mtl-2.0.1.0 -> 2.1.1 regex-tdfa-1.1.8 (reinstall) changes: mtl-2.0.1.0 -> 2.1.1 buildwrapper-0.5.2 (new package)
And that build wrapper doesn't have a defined dependency version number for MTL can someone tell me why cabal is trying to install a new version of MTL ?
Thanks