From 6c4fd2e3df5124dd625711135d82e39f2220d7e3 Mon Sep 17 00:00:00 2001
From: Eelco Dolstra <eelco.dolstra@logicblox.com>
Date: Tue, 11 Sep 2007 13:48:53 +0000
Subject: [PATCH] * Allow the user to override the list of content-addressable
 mirrors   from the command-line by setting the NIX_HASHED_MIRRORS environment
   variable.

svn path=/nixpkgs/trunk/; revision=9301
---
 pkgs/build-support/fetchurl/builder.sh  |  4 ++++
 pkgs/build-support/fetchurl/default.nix | 16 +++++++++++-----
 2 files changed, 15 insertions(+), 5 deletions(-)

diff --git a/pkgs/build-support/fetchurl/builder.sh b/pkgs/build-support/fetchurl/builder.sh
index f91edf7c281..511839655be 100644
--- a/pkgs/build-support/fetchurl/builder.sh
+++ b/pkgs/build-support/fetchurl/builder.sh
@@ -46,6 +46,10 @@ finish() {
 
 
 tryHashedMirrors() {
+    if test -n "$NIX_HASHED_MIRRORS"; then
+        hashedMirrors="$NIX_HASHED_MIRRORS"
+    fi
+    
     for mirror in $hashedMirrors; do
         url="$mirror/$outputHashAlgo/$outputHash"
         if $curl --fail --silent --show-error --head "$url" \
diff --git a/pkgs/build-support/fetchurl/default.nix b/pkgs/build-support/fetchurl/default.nix
index eb40c4c6a91..e752b9313e9 100644
--- a/pkgs/build-support/fetchurl/default.nix
+++ b/pkgs/build-support/fetchurl/default.nix
@@ -52,11 +52,17 @@ stdenv.mkDerivation ({
   outputHash = if outputHash != "" then outputHash else
       if sha256 != "" then sha256 else if sha1 != "" then sha1 else md5;
   
-  # 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.
-  impureEnvVars = ["http_proxy" "https_proxy" "ftp_proxy" "all_proxy" "no_proxy"];
+  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"
+
+    # This variable allows the user to override hashedMirrors from the
+    # command-line.
+    "NIX_HASHED_MIRRORS"
+  ];
 }
 
 # Pass the mirror locations to the builder.