Remove `unpackCmd's not needed with GNU tar format auto-detection (r18492).

svn path=/nixpkgs/branches/stdenv-updates/; revision=18653

pkgs/applications/graphics/pqiv/default.nix

@@ -4,14 +4,12 @@ stdenv.mkDerivation (rec {
   name = "pqiv-0.8";
 
   src = fetchurl {
-    url = "http://www.pberndt.com/raw//Programme/Linux/pqiv/_download/pqiv-0.8.tbz";
+    url = "http://www.pberndt.com/raw/Programme/Linux/pqiv/_download/${name}.tbz";
     sha256 = "365332bab4b13ca56da6935e7155af20658e67d323808942dce23e880466f66d";
   };
 
   buildInputs = [ getopt which pkgconfig gtk ];
 
-  unpackCmd="bzip2 -d < $src | tar xvf - || fail";
-
   preConfigure=''
     substituteInPlace configure --replace /bin/bash "$shell"
     sed -i -e 's|$(tempfile -s.*)|temp.c|' -e 's|tempfile|mktemp|' configure

pkgs/development/tools/misc/autoconf/2.13.nix

@@ -9,8 +9,6 @@ stdenv.mkDerivation rec {
   };
 
   buildInputs = [m4 perl lzma];
-  
-  unpackCmd = "lzma -d < $src | tar -x ";
 
   doCheck = true;
 

pkgs/development/tools/misc/libtool/libtool2.nix

@@ -10,8 +10,6 @@ stdenv.mkDerivation rec {
 
   buildNativeInputs = [ lzma m4 perl ];
 
-  unpackCmd = "lzma -d < $src | tar xv";
-
   # Don't fixup "#! /bin/sh" in Libtool, otherwise it will use the
   # "fixed" path in generated files!
   dontPatchShebangs = true;

pkgs/development/tools/misc/texinfo/default.nix

@@ -10,8 +10,6 @@ stdenv.mkDerivation rec {
 
   buildInputs = [ ncurses lzma ];
 
-  unpackCmd = "lzma -d < $src | tar xv";
-
   # Disabled because we don't have zdiff in the stdenv bootstrap.
   #doCheck = true;