From 470ade254e73e280b0ec9e1a1ef081926e0d1371 Mon Sep 17 00:00:00 2001
From: Peter Simons <simons@cryp.to>
Date: Thu, 6 Sep 2012 14:59:07 +0200
Subject: [PATCH] Add support for jailbreak-cabal utility to the Cabal builder.

Jailbreaks-cabal allows Nixpkgs maintainers to quick-fix builds of packages
that over-specify their version requirements by removing the version
restrictions of all dependencies from the Cabal file. Set

  jailbreak = true

in the build expression to activate this feature.
---
 pkgs/build-support/cabal/default.nix | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/pkgs/build-support/cabal/default.nix b/pkgs/build-support/cabal/default.nix
index 8ae8c06d5132..42392aff60c4 100644
--- a/pkgs/build-support/cabal/default.nix
+++ b/pkgs/build-support/cabal/default.nix
@@ -1,6 +1,6 @@
 # generic builder for Cabal packages
 
-{stdenv, fetchurl, lib, pkgconfig, ghc, Cabal, enableLibraryProfiling ? false} :
+{ stdenv, fetchurl, lib, pkgconfig, ghc, Cabal, jailbreakCabal, enableLibraryProfiling ? false }:
 {
   mkDerivation =
     args : # arguments for the individual package, can modify the defaults
@@ -86,7 +86,8 @@
             configurePhase = ''
               eval "$preConfigure"
 
-              for i in Setup.hs Setup.lhs; do
+              ${lib.optionalString (lib.attrByPath ["jailbreak"] false self) "${jailbreakCabal}/bin/jailbreak-cabal ${self.pname}.cabal && "
+              }for i in Setup.hs Setup.lhs; do
                 test -f $i && ghc --make $i
               done