From 91c130e2f5d6702e195dd6c25abafc5f16b7e505 Mon Sep 17 00:00:00 2001
From: zimbatm <zimbatm@zimbatm.com>
Date: Tue, 13 Nov 2018 12:35:10 +0100
Subject: [PATCH] libredirect: introduce optional setup-hook

This allows to simplify the usage of libredirect inside of nix build
sandboxes. Add "libredirect.hook" to the build inputs to get everything
linked in automaticall. All that's left is to set NIX_REDIRECTS and call
the target program.
---
 pkgs/build-support/libredirect/default.nix | 24 +++++++++++++++-------
 1 file changed, 17 insertions(+), 7 deletions(-)

diff --git a/pkgs/build-support/libredirect/default.nix b/pkgs/build-support/libredirect/default.nix
index e92945a4030..7caca2fc003 100644
--- a/pkgs/build-support/libredirect/default.nix
+++ b/pkgs/build-support/libredirect/default.nix
@@ -10,6 +10,8 @@ stdenv.mkDerivation {
 
   libName = "libredirect" + stdenv.targetPlatform.extensions.sharedLibrary;
 
+  outputs = ["out" "hook"];
+
   buildPhase = ''
     $CC -Wall -std=c99 -O3 -shared libredirect.c \
       -o "$libName" -fPIC -ldl
@@ -21,17 +23,25 @@ stdenv.mkDerivation {
 
   installPhase = ''
     install -vD "$libName" "$out/lib/$libName"
+
+    mkdir -p "$hook/nix-support"
+    cat <<SETUP_HOOK > "$hook/nix-support/setup-hook"
+    ${if stdenv.isDarwin then ''
+    export DYLD_INSERT_LIBRARIES="$out/lib/$libName"
+    export DYLD_FORCE_FLAT_NAMESPACE=1
+    '' else ''
+    export LD_PRELOAD="$out/lib/$libName"
+    ''}
+    SETUP_HOOK
   '';
 
   doInstallCheck = true;
 
-  installCheckPhase = if stdenv.isDarwin then ''
-    NIX_REDIRECTS="/foo/bar/test=${coreutils}/bin/true" \
-    DYLD_INSERT_LIBRARIES="$out/lib/$libName" \
-    DYLD_FORCE_FLAT_NAMESPACE=1 ./test
-  '' else ''
-    NIX_REDIRECTS="/foo/bar/test=${coreutils}/bin/true" \
-    LD_PRELOAD="$out/lib/$libName" ./test
+  installCheckPhase = ''
+    (
+      source "$hook/nix-support/setup-hook"
+      NIX_REDIRECTS="/foo/bar/test=${coreutils}/bin/true" ./test
+    )
   '';
 
   meta = {