Description: use the shadow implementation on gnu systems
 Let extconf knows that it can use the shadow functions, just like on Linux,
 on Debian archs like kFreeBSD and Hurd.

Bug-Debian: http://bugs.debian.org/749904
Reviewed-By: David Suárez <david.sephirot@gmail.com>
Author: Samuel Thibault <sthibault@debian.org>
Last-Update: 2014-06-01

--- a/extconf.rb
+++ b/extconf.rb
@@ -11,6 +11,7 @@ $CFLAGS += ' -DRUBY19'
 
 implementation = case CONFIG['host_os']
                  when /linux/i; 'shadow'
+                 when /gnu/i; 'shadow' # Debian GNU/kFreeBSD and Hurd have shadow.h
                  when /sunos|solaris/i; 'shadow'
                  when /freebsd|mirbsd|netbsd|openbsd/i; 'pwd'
                  when /darwin/i; 'pwd'
