nix: generate shell fix env flags.

pkgs/shell-generate.nix

@@ -1,63 +1,59 b''
 { pkgs ? (import <nixpkgs> {})
 , pythonPackages ? "python27Packages"
 }:
 
 with pkgs.lib;
 
 let
   _pythonPackages = pythonPackages;
 
 in
 
 let
   pythonPackages = getAttr _pythonPackages pkgs;
 
   pip2nix = import ./nix-common/pip2nix.nix {
     inherit
       pkgs
       pythonPackages;
   };
 
 in
 
 pkgs.stdenv.mkDerivation {
   name = "pip2nix-generated";
 
   buildInputs = [
     # Allows to generate python packages
     pip2nix.pip2nix
     pythonPackages.pip-tools
     # compile using ffi
     pkgs.libffi
 
     pkgs.apr
     pkgs.aprutil
   ];
 
-  LC_ALL = "en_US.UTF-8";
-  LOCALE_ARCHIVE =
-    if pkgs.stdenv.isLinux
-    then "${pkgs.glibcLocales}/lib/locale/locale-archive"
-    else "";
-
   shellHook = ''
     runHook preShellHook
     echo "Setting SVN_* variables"
     export SVN_LIBRARY_PATH=${pkgs.subversion}/lib
     export SVN_HEADER_PATH=${pkgs.subversion.dev}/include
     runHook postShellHook
   '';
 
   preShellHook = ''
     echo "Starting Generate Shell"
     # set unpack source date to 1980 to fix ZIP problems that does not support <1980
     export SOURCE_DATE_EPOCH=315532800
     export TMPDIR=/tmp
+    export LOCALE_ARCHIVE="${pkgs.glibcLocales}/lib/locale/locale-archive"
+    export LC_ALL="en_US.UTF-8"
 
     # Custom prompt to distinguish from other dev envs.
     export PS1="\n\[\033[1;32m\][pip2nix-generate-shell]$\[\033[0m\] "
 
     export PYCURL_SSL_LIBRARY=openssl
 
   '';
 }