From 0ff88fb2abda84d54560d2421bfd70082bec65d7 Mon Sep 17 00:00:00 2001
From: Peter Simons <simons@cryp.to>
Date: Sat, 10 Mar 2018 13:13:37 +0100
Subject: [PATCH] haskell-GenericPretty: apply upstream patch to fix the build
 with ghc 8.4.x

---
 .../haskell-modules/configuration-ghc-8.4.x.nix            | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/pkgs/development/haskell-modules/configuration-ghc-8.4.x.nix b/pkgs/development/haskell-modules/configuration-ghc-8.4.x.nix
index 5114708b6d2..a8d79dcddc2 100644
--- a/pkgs/development/haskell-modules/configuration-ghc-8.4.x.nix
+++ b/pkgs/development/haskell-modules/configuration-ghc-8.4.x.nix
@@ -790,4 +790,11 @@ self: super: {
   # Older versions don't compile.
   hackage-db = super.hackage-db_2_0_1;
 
+  # https://github.com/RazvanRanca/GenericPretty/issues/2
+  GenericPretty = appendPatch super.GenericPretty (pkgs.fetchpatch
+    { url = https://github.com/RazvanRanca/GenericPretty/pull/3.patch;
+      sha256 = "1dpdqsjmy9j9b6md5r9jyhbxnxjd51nmfb5in01j10iqzhj9j51k";
+    }
+  );
+
 }