From 291b05ee21a6b822e999566febf9e419e45936da Mon Sep 17 00:00:00 2001
From: Andreas Rammhold <andreas@rammhold.de>
Date: Wed, 7 Feb 2018 11:37:30 +0100
Subject: [PATCH] squid4: hack to detect our libxml2

---
 pkgs/servers/squid/4.nix | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/pkgs/servers/squid/4.nix b/pkgs/servers/squid/4.nix
index 62f0b7c001b..4a4502a6939 100644
--- a/pkgs/servers/squid/4.nix
+++ b/pkgs/servers/squid/4.nix
@@ -13,6 +13,10 @@ stdenv.mkDerivation rec {
     perl openldap db cyrus_sasl expat libxml2 openssl
   ] ++ stdenv.lib.optionals stdenv.isLinux [ libcap pam ];
 
+  prePatch = ''
+    substituteInPlace configure --replace "/usr/local/include/libxml2" "${libxml2.dev}/include/libxml2"
+  '';
+
   configureFlags = [
     "--enable-ipv6"
     "--disable-strict-error-checking"