Add an option ‘stdenv.userHook’ to set a global stdenv setup hook

This allows various applications.  It allows users to set global
optimisation flags, e.g.

  stdenv.userHook = ''NIX_CFLAGS_COMPILE+=" -funroll-loops"'';

But the impetus is as an alternative to issue #229, allowing impure
stdenv setup for people who want to use distcc:

  stdenv.userHook = "source /my/impure/setup-script.sh";

This is probably a bad idea, but at least now it's a bad idea in
people's configuration and not in Nixpkgs. :-)

1 files changed, 3 insertions, 1 deletions

diff --git a/pkgs/stdenv/nix/default.nix b/pkgs/stdenv/nix/default.nix
index 5e242b6e3a1c..668bac5f0ae8 100644
--- a/pkgs/stdenv/nix/default.nix
+++ b/pkgs/stdenv/nix/default.nix
@@ -1,6 +1,8 @@
-{ stdenv, pkgs }:
+{ stdenv, pkgs, config }:
 
 import ../generic rec {
+  inherit config;
+
   preHook =
     ''
       export NIX_ENFORCE_PURITY=1