Consistently pass through PKG_CONFIG_LIBDIR environment variable

src/platform/theme/SConstruct

Index: src/platform/theme/SConstruct
diff --git a/src/platform/theme/SConstruct b/src/platform/theme/SConstruct
index 09e26da89cbdd41962b633f7aa37655714916185..4ee3063fc1333127e5526011e3e256e8e8beabf0 100644
--- a/src/platform/theme/SConstruct
+++ b/src/platform/theme/SConstruct
@@ -17,6 +17,11 @@ for key in Split('CC CXX AR RANLIB LD NM CFLAGS CCFLAGS'):
   if value != None:
     env[key] = value
 
+# Fix up the pkg-config path if it is present in the environment.
+for key in Split('PKG_CONFIG_LIBDIR PKG_CONFIG_PATH'):
+  if os.environ.has_key(key):
+    env['ENV'][key] = os.environ[key]
+
 env.ParseConfig('pkg-config --cflags --libs gtk+-2.0 glib-2.0')
 
 env.SharedLibrary('theme', SOURCES)