From ab9515092b291fb92cf83a21c2a344a096ae8474 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Vladim=C3=ADr=20=C4=8Cun=C3=A1t?= <vladimir.cunat@nic.cz>
Date: Thu, 14 Jul 2016 15:30:30 +0200
Subject: [PATCH] symlinkJoin: truly pass the defaulted parameters

The catch is that in nix the @-pattern binds the set that was *explicitly*
passed to the function, i.e. default values are *not* taken into account.
---
 pkgs/build-support/trivial-builders.nix | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/pkgs/build-support/trivial-builders.nix b/pkgs/build-support/trivial-builders.nix
index 18e49105ae78..8775286b1172 100644
--- a/pkgs/build-support/trivial-builders.nix
+++ b/pkgs/build-support/trivial-builders.nix
@@ -49,15 +49,17 @@ rec {
 
   # Create a forest of symlinks to the files in `paths'.
   symlinkJoin =
-    args@{ name
+    args_@{ name
          , paths
          , preferLocalBuild ? true
          , allowSubstitutes ? false
          , postBuild ? ""
          , ...
          }:
-    runCommand name
-      (removeAttrs args [ "name" "postBuild" ])
+    let
+      args = removeAttrs args_ [ "name" "postBuild" ]
+        // { inherit preferLocalBuild allowSubstitutes; }; # pass the defaults
+    in runCommand name args
       ''
         mkdir -p $out
         for i in $paths; do