git clone 'git://github.com/flycheck/flycheck-haskell.git'
Configure Flycheck for Haskell:
As usual, from MELPA or MELPA Stable.
(source gnu) (source melpa) (depends-on "flycheck-haskell")
(eval-after-load 'flycheck '(add-hook 'flycheck-mode-hook #'flycheck-haskell-setup))
Just use Flycheck as usual in your Cabal projects.
To explicitly configure Haskell syntax checking for the current buffer, type M-x flycheck-haskell-configure. You should run this command after major changes to the Cabal file.
This program is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version.
This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.
You should have received a copy of the GNU General Public License along with this program. If not, see http://www.gnu.org/licenses/.
COPYING for details.