07/177: gnu: ghc-mtl: Fix build with GHC 8.

[Ricardo Wurmus]

rekado pushed a commit to branch master
in repository guix.

commit c088e393410b786b4d5aab87e27a5b6bf8b9082d
Author: Ricardo Wurmus <address@hidden>
Date:   Mon Feb 12 19:04:25 2018 +0100

    gnu: ghc-mtl: Fix build with GHC 8.
    
    * gnu/packages/haskell.scm (ghc-mtl)[inputs]: Add ghc-transformers.
    [arguments]: Permit building with newer version of transformers.
---
 gnu/packages/haskell.scm | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/gnu/packages/haskell.scm b/gnu/packages/haskell.scm
index 5857540..c6a8376 100644
--- a/gnu/packages/haskell.scm
+++ b/gnu/packages/haskell.scm
@@ -1479,6 +1479,10 @@ installation of Haskell libraries and programs.")
         (base32
          "1icdbj2rshzn0m1zz5wa7v3xvkf6qw811p4s7jgqwvx1ydwrvrfa"))))
     (build-system haskell-build-system)
+    (arguments
+     `(#:configure-flags (list "--allow-newer=transformers")))
+    (inputs
+     `(("ghc-transformers" ,ghc-transformers)))
     (home-page "https://github.com/ekmett/mtl";)
     (synopsis
      "Monad classes, using functional dependencies")