From 9bbfc6f6e2c7d84136d344ca3182a47cb14cb32b Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?J=C3=B6rg=20Thalheim?= <joerg@thalheim.io>
Date: Sun, 28 Oct 2018 13:45:56 +0000
Subject: [PATCH] buildGoPackage: re-enable GOCACHE

If projects uses go1.11 modules GOCACHE is required.
Also if buildGoPackage is used in a nix-shell setting we don't
want to override GOCACHE to allow incremental builds.
This should be backported to 18.09
---
 pkgs/development/go-modules/generic/default.nix | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/pkgs/development/go-modules/generic/default.nix b/pkgs/development/go-modules/generic/default.nix
index 3faa4c268ac0..0e092473bd52 100644
--- a/pkgs/development/go-modules/generic/default.nix
+++ b/pkgs/development/go-modules/generic/default.nix
@@ -103,6 +103,7 @@ go.stdenv.mkDerivation (
 
   '') + ''
     export GOPATH=$NIX_BUILD_TOP/go:$GOPATH
+    export GOCACHE=$TMPDIR/go-cache
 
     runHook postConfigure
   '';
@@ -193,9 +194,6 @@ go.stdenv.mkDerivation (
     find $bin/bin -type f -exec ${removeExpr removeReferences} '{}' + || true
   '';
 
-  # Disable go cache, which is not reused in nix anyway
-  GOCACHE = "off";
-
   shellHook = ''
     d=$(mktemp -d "--suffix=-$name")
   '' + toString (map (dep: ''