From 49446109035a8e041dcd57759af3226ab9b0337d Mon Sep 17 00:00:00 2001
From: Peter Simons <simons@cryp.to>
Date: Thu, 14 Sep 2017 14:53:47 +0200
Subject: [PATCH] haskell-cryptol: override happy to older version to fix the
 build

---
 pkgs/development/haskell-modules/configuration-common.nix | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/pkgs/development/haskell-modules/configuration-common.nix b/pkgs/development/haskell-modules/configuration-common.nix
index abff9dfee4dc..77c94f9f2502 100644
--- a/pkgs/development/haskell-modules/configuration-common.nix
+++ b/pkgs/development/haskell-modules/configuration-common.nix
@@ -929,6 +929,9 @@ self: super: {
   # https://hydra.nixos.org/build/60678124
   Agda = markBroken (super.Agda.override { happy = self.happy_1_19_5; });
 
+  # cryptol-2.5.0 doesn't want happy 1.19.6+.
+  cryptol = super.cryptol.override { happy = self.happy_1_19_5; };
+
   # https://github.com/jtdaugherty/text-zipper/issues/11
   text-zipper = dontCheck super.text-zipper;