From c752d37efe1755bffc19d09fdf82d3c98a12e76e Mon Sep 17 00:00:00 2001
From: Peter Simons <simons@cryp.to>
Date: Fri, 1 May 2020 21:22:22 +0200
Subject: [PATCH] cabal-install: patch the ghc-8.10.x build to succeed

---
 .../haskell-modules/configuration-ghc-8.10.x.nix  | 15 +++++++++++++++
 1 file changed, 15 insertions(+)

diff --git a/pkgs/development/haskell-modules/configuration-ghc-8.10.x.nix b/pkgs/development/haskell-modules/configuration-ghc-8.10.x.nix
index 206577e3e8e0..61919055eb0a 100644
--- a/pkgs/development/haskell-modules/configuration-ghc-8.10.x.nix
+++ b/pkgs/development/haskell-modules/configuration-ghc-8.10.x.nix
@@ -42,6 +42,21 @@ self: super: {
   unix = null;
   xhtml = null;
 
+  # The proper 3.2.0.0 release does not compile with ghc-8.10.1, so we take the
+  # hitherto unreleased next version from the '3.2' branch of the upstream git
+  # repository for the time being.
+  cabal-install = assert super.cabal-install.version == "3.2.0.0";
+                  overrideCabal super.cabal-install (drv: {
+    postUnpack = "sourceRoot+=/cabal-install; echo source root reset to $sourceRoot";
+    version = "3.2.0.0-git";
+    editedCabalFile = null;
+    src = pkgs.fetchgit {
+      url = "git://github.com/haskell/cabal.git";
+      rev = "9bd4cc0591616aeae78e17167338371a2542a475";
+      sha256 = "005q1shh7vqgykkp72hhmswmrfpz761x0q0jqfnl3wqim4xd9dg0";
+    };
+  });
+
   # Deviate from Stackage LTS-15.x to fix the build.
   haddock-library = self.haddock-library_1_9_0;