From fa13d3f4f3d8fb6dc3e3fc87ac5a2e26d8b32d84 Mon Sep 17 00:00:00 2001
From: Eelco Dolstra <eelco.dolstra@logicblox.com>
Date: Mon, 14 Jul 2014 12:19:27 +0200
Subject: [PATCH] build-remote.pl: Fix building multiple output derivations

We were importing paths without sorting them topologically, leading to
"path is not valid" errors.

See e.g. http://hydra.nixos.org/build/12451761
---
 src/libstore/remote-store.cc | 1 -
 src/nix-store/nix-store.cc   | 4 +++-
 tests/remote-builds.nix      | 5 +++--
 3 files changed, 6 insertions(+), 4 deletions(-)

diff --git a/src/libstore/remote-store.cc b/src/libstore/remote-store.cc
index f566ccf53..3b021bb2a 100644
--- a/src/libstore/remote-store.cc
+++ b/src/libstore/remote-store.cc
@@ -35,7 +35,6 @@ template<class T> T readStorePaths(Source & from)
 }
 
 template PathSet readStorePaths(Source & from);
-template Paths readStorePaths(Source & from);
 
 
 RemoteStore::RemoteStore()
diff --git a/src/nix-store/nix-store.cc b/src/nix-store/nix-store.cc
index 0196c2fc1..048f5c603 100644
--- a/src/nix-store/nix-store.cc
+++ b/src/nix-store/nix-store.cc
@@ -992,7 +992,9 @@ static void opServe(Strings opFlags, Strings opArgs)
             }
 
             case cmdExportPaths: {
-                exportPaths(*store, readStorePaths<Paths>(in), false, out);
+                Paths sorted = topoSortPaths(*store, readStorePaths<PathSet>(in));
+                reverse(sorted.begin(), sorted.end());
+                exportPaths(*store, sorted, false, out);
                 break;
             }
 
diff --git a/tests/remote-builds.nix b/tests/remote-builds.nix
index 571cdfbdd..eb80a7d7e 100644
--- a/tests/remote-builds.nix
+++ b/tests/remote-builds.nix
@@ -25,7 +25,8 @@ let
         system = "i686-linux";
         PATH = "''${utils}/bin";
         builder = "''${utils}/bin/sh";
-        args = [ "-c" "echo Hello; mkdir $out; cat /proc/sys/kernel/hostname > $out/host; sleep 3" ];
+        args = [ "-c" "echo Hello; mkdir $out $foo; cat /proc/sys/kernel/hostname > $out/host; ln -s $out $foo/bar; sleep 5" ];
+        outputs = [ "out" "foo" ];
       }
     '';
 
@@ -86,7 +87,7 @@ in
 
       # And a parallel build.
       my ($out1, $out2) = split /\s/,
-          $client->succeed("nix-store -r \$(nix-instantiate ${expr nodes.client.config 2} ${expr nodes.client.config 3})");
+          $client->succeed('nix-store -r $(nix-instantiate ${expr nodes.client.config 2})\!out $(nix-instantiate ${expr nodes.client.config 3})\!out');
       $slave1->succeed("test -e $out1 -o -e $out2");
       $slave2->succeed("test -e $out1 -o -e $out2");