58/118: Pass *_proxy vars to bootstrap fetchurl

[Ludovic Courtès]

civodul pushed a commit to branch nix
in repository guix.

commit 048be62484537633e2523dd4d200619649ff860d
Author: Shea Levy <address@hidden>
Date:   Wed Jul 16 01:11:24 2014 -0400

    Pass *_proxy vars to bootstrap fetchurl
---
 corepkgs/fetchurl.nix |    8 ++++++++
 1 files changed, 8 insertions(+), 0 deletions(-)

diff --git a/corepkgs/fetchurl.nix b/corepkgs/fetchurl.nix
index 39b9dd5..4faedb1 100644
--- a/corepkgs/fetchurl.nix
+++ b/corepkgs/fetchurl.nix
@@ -34,4 +34,12 @@ derivation {
 
   # Don't build in a chroot because Nix's dependencies may not be there.
   __noChroot = true;
+
+  impureEnvVars = [
+    # We borrow these environment variables from the caller to allow
+    # easy proxy configuration.  This is impure, but a fixed-output
+    # derivation like fetchurl is allowed to do so since its result is
+    # by definition pure.
+    "http_proxy" "https_proxy" "ftp_proxy" "all_proxy" "no_proxy"
+  ];
 }