build: find Boost lib architecture automatically

refs #4573

Change-Id: Ie58f18c0634a837b303e290018f8a9a5bb71f5c7
diff --git a/.waf-tools/boost.py b/.waf-tools/boost.py
index 9b9395e..d7e0107 100644
--- a/.waf-tools/boost.py
+++ b/.waf-tools/boost.py
@@ -54,8 +54,7 @@
 from waflib.Configure import conf
 from waflib.TaskGen import feature, after_method
 
-BOOST_LIBS = ['/usr/lib/x86_64-linux-gnu', '/usr/lib/i386-linux-gnu',
-			  '/usr/lib', '/usr/local/lib', '/opt/local/lib', '/sw/lib', '/lib']
+BOOST_LIBS = ['/usr/lib', '/usr/local/lib', '/opt/local/lib', '/sw/lib', '/lib']
 BOOST_INCLUDES = ['/usr/include', '/usr/local/include', '/opt/local/include', '/sw/include']
 BOOST_VERSION_FILE = 'boost/version.hpp'
 BOOST_VERSION_CODE = '''
@@ -404,6 +403,11 @@
 
 	var = kw.get('uselib_store', 'BOOST')
 
+	self.find_program('dpkg-architecture', var='DPKG_ARCHITECTURE', mandatory=False)
+	if self.env.DPKG_ARCHITECTURE:
+		deb_host_multiarch = self.cmd_and_log([self.env.DPKG_ARCHITECTURE[0], '-qDEB_HOST_MULTIARCH'])
+		BOOST_LIBS.insert(0, '/usr/lib/%s' % deb_host_multiarch.strip())
+
 	self.start_msg('Checking boost includes')
 	self.env['INCLUDES_%s' % var] = inc = self.boost_get_includes(**params)
 	versions = self.boost_get_version(inc)