Description: Don't overwrite CFLAGS|LDFLAGS
 It seems that the current extconf.rb overwrites the CFLAGS/LDFLAGS.

Author: Cédric Boutillier <boutil@debian.org>
Author: David Suárez <david.sephirot@gmail.com>
Last-Update: 2013-10-26

Index: ruby-shadow/extconf.rb
===================================================================
--- ruby-shadow.orig/extconf.rb
+++ ruby-shadow/extconf.rb
@@ -7,12 +7,7 @@
 require 'mkmf'
 require 'rbconfig'
 
-$CFLAGS = case RUBY_VERSION
-          when /^1\.9/; '-DRUBY19'
-          when /^2\./; '-DRUBY19'
-          when /^3\./; '-DRUBY19'
-          else; ''
-          end
+$CFLAGS += ' -DRUBY19'
 
 implementation = case CONFIG['host_os']
                  when /linux/i; 'shadow'
@@ -30,7 +25,7 @@ when 'shadow'
   #$LDFLAGS = "-lshadow"
 
   if( ! (ok &= have_library("shadow","getspent")) )
-    $LDFLAGS = ""
+    #$LDFLAGS = ""
     ok = have_func("getspent")
   end
 
