From 46f852cda013b818f113c7905f020131a44f2340 Mon Sep 17 00:00:00 2001
From: Eelco Dolstra <eelco.dolstra@logicblox.com>
Date: Wed, 1 Aug 2012 16:42:51 -0400
Subject: [PATCH] Use a GNU tar flag to shut up warnings about implausibly old
 timestamp

---
 configure.ac                | 12 ++++++++++++
 corepkgs/config.nix.in      |  1 +
 corepkgs/unpack-channel.nix |  2 +-
 substitute.mk               |  1 +
 4 files changed, 15 insertions(+), 1 deletion(-)

diff --git a/configure.ac b/configure.ac
index 21a87194..bbee7b06 100644
--- a/configure.ac
+++ b/configure.ac
@@ -339,6 +339,18 @@ eval dynlib_suffix=$shrext_cmds
 AC_SUBST(dynlib_suffix)
 
 
+# Do we have GNU tar?
+AC_MSG_CHECKING([if you have GNU tar])
+if $tar --version 2> /dev/null | grep -q GNU; then
+    AC_MSG_RESULT(yes)
+    tarFlags="--warning=no-timestamp"
+else
+    AC_MSG_RESULT(no)
+fi
+AC_SUBST(tarFlags)
+
+
+
 AM_CONFIG_HEADER([config.h])
 AC_CONFIG_FILES([Makefile
    src/Makefile
diff --git a/corepkgs/config.nix.in b/corepkgs/config.nix.in
index 26e821d0..6f6ec6de 100644
--- a/corepkgs/config.nix.in
+++ b/corepkgs/config.nix.in
@@ -9,6 +9,7 @@ in {
   bzip2 = "@bzip2@";
   xz = "@xz@";
   tar = "@tar@";
+  tarFlags = "@tarFlags@";
   tr = "@tr@";
   curl = "@curl@";
   nixBinDir = fromEnv "NIX_BIN_DIR" "@bindir@";
diff --git a/corepkgs/unpack-channel.nix b/corepkgs/unpack-channel.nix
index b26bece3..bbc54c7d 100644
--- a/corepkgs/unpack-channel.nix
+++ b/corepkgs/unpack-channel.nix
@@ -6,7 +6,7 @@ let
     ''
       mkdir $out
       cd $out
-      ${bzip2} -d < $src | ${tar} xf -
+      ${bzip2} -d < $src | ${tar} xf - --warning=no-timestamp 
       mv * $out/$channelName
     '';
 
diff --git a/substitute.mk b/substitute.mk
index 77c5afc2..37875194 100644
--- a/substitute.mk
+++ b/substitute.mk
@@ -22,6 +22,7 @@
 	 -e "s^@coreutils\@^$(coreutils)^g" \
 	 -e "s^@sed\@^$(sed)^g" \
 	 -e "s^@tar\@^$(tar)^g" \
+	 -e "s^@tarFlags\@^$(tarFlags)^g" \
 	 -e "s^@gzip\@^$(gzip)^g" \
 	 -e "s^@pv\@^$(pv)^g" \
 	 -e "s^@tr\@^$(tr)^g" \