Fix build problem.

CHANGELOG

@@ -1,4 +1,6 @@
 
+v0.15.1. Fix build problem.
+
 v0.15. Update to libmemcached 0.31.1. UDP support. Domain socket support (hellvinz). Bugfixes. Bundle libmemcached itself with the gem (antifuchs).
 
 v0.14.4. Re-SWIG.

ext/extconf.rb

@@ -5,10 +5,10 @@ HERE = File.expand_path(File.dirname(__FILE__))
 BUNDLE = Dir.glob("libmemcached-*.tar.gz").first
 BUNDLE_PATH = BUNDLE.sub(".tar.gz", "")
 
-$includes = ENV['INCLUDE_PATH'].to_s.split(':').map{|s| " -I#{s}"}.uniq.join
+$LIBS << " -lmemcached"
 
 if !ENV["EXTERNAL_LIB"]
-  $includes = " -I#{HERE}/include" + $includes
+  $includes = " -I#{HERE}/include"
   $libraries = " -L#{HERE}/lib"
 
   $CFLAGS = "#{$includes} #{$libraries} #{$CFLAGS}"
@@ -35,6 +35,8 @@ if !ENV["EXTERNAL_LIB"]
       system("rm -rf #{BUNDLE_PATH}")
     end      
   end
+  
+  find_header('libmemcached/memcached.h', "#{HERE}/include") or raise
 end
 
 if ENV['SWIG']

lib/memcached.rb

@@ -22,7 +22,7 @@ class Memcached
   Lib = Rlibmemcached
   REQUIRED_VERSION = File.read("#{File.dirname(__FILE__)}/../COMPATIBILITY")[/:: ([\d\.]+)/, 1]
   RECEIVED_VERSION = Lib.memcached_lib_version
-  STDERR.puts "Warning: libmemcached #{REQUIRED_VERSION} suggested; you have #{RECEIVED_VERSION}." unless REQUIRED_VERSION == RECEIVED_VERSION
+  raise "libmemcached #{REQUIRED_VERSION} required; your gem is linked to #{RECEIVED_VERSION}." unless REQUIRED_VERSION == RECEIVED_VERSION
 end
 
 require 'memcached/integer'