Fix tarball build

pkgs/applications/networking/browsers/firefox-bin/default.nix

@@ -37,6 +37,8 @@
 , systemd
 }:
 
+assert stdenv.isLinux;
+
 let
   version = "31.0";
   sources = [

pkgs/applications/networking/mailreaders/thunderbird-bin/default.nix

@@ -37,6 +37,8 @@
 , pango
 }:
 
+assert stdenv.isLinux;
+
 let
   version = "31.0";
   sources = [

pkgs/development/compilers/go/1.3.nix

@@ -1,5 +1,7 @@
 { stdenv, lib, fetchurl, bison, glibc, bash, coreutils, makeWrapper, tzdata, iana_etc }:
 
+assert stdenv.gcc.gcc != null;
+
 let
   loader386 = "${glibc}/lib/ld-linux.so.2";
   loaderAmd64 = "${glibc}/lib/ld-linux-x86-64.so.2";

pkgs/development/compilers/rustc/0.11.nix

@@ -1,5 +1,7 @@
 {stdenv, fetchurl, which, file, perl, curl, python27, makeWrapper}:
 
+assert stdenv.gcc.gcc != null;
+
 /* Rust's build process has a few quirks :
 
 - It requires some patched in llvm that haven't landed upstream, so it

pkgs/development/compilers/rustc/head.nix

@@ -1,5 +1,7 @@
 {stdenv, fetchurl, fetchgit, which, file, perl, curl, python27, makeWrapper}:
 
+assert stdenv.gcc.gcc != null;
+
 /* Rust's build process has a few quirks :
 
 - It requires some patched in llvm that haven't landed upstream, so it

pkgs/development/libraries/glib/default.nix

@@ -7,6 +7,8 @@
 
 with stdenv.lib;
 
+assert stdenv.gcc.gcc != null;
+
 # TODO:
 # * Add gio-module-fam
 #     Problem: cyclic dependency on gamin

pkgs/games/adom/default.nix

@@ -1,6 +1,8 @@
 { stdenv, patchelf, zlib, libmad, libpng12, libcaca, mesa, alsaLib, pulseaudio
 , xlibs, plowshare }:
 
+assert stdenv.isLinux;
+
 let
 
   inherit (xlibs) libXext libX11;

pkgs/servers/nosql/influxdb/default.nix

@@ -1,5 +1,7 @@
 { stdenv, fetchurl, makeWrapper }:
 
+assert stdenv.isLinux;
+
 stdenv.mkDerivation rec {
   name = "influxdb-${version}";
   version = "0.7.0";

pkgs/tools/filesystems/yandex-disk/default.nix

@@ -1,4 +1,7 @@
 { stdenv, fetchurl, writeText, zlib, rpm, cpio, patchelf, which }:
+
+assert stdenv.isLinux;
+
 let
   p = if stdenv.is64bit then {
       arch = "x86_64";