Fixed #3386: the optional prefix argument was ignored under OS2 and NT in distutils.sysconfig.get_python_lib
diff --git a/Lib/distutils/sysconfig.py b/Lib/distutils/sysconfig.py
index 4e06546..56cb861 100644
--- a/Lib/distutils/sysconfig.py
+++ b/Lib/distutils/sysconfig.py
@@ -132,7 +132,7 @@
             if get_python_version() < "2.2":
                 return prefix
             else:
-                return os.path.join(PREFIX, "Lib", "site-packages")
+                return os.path.join(prefix, "Lib", "site-packages")
 
     elif os.name == "mac":
         if plat_specific:
@@ -148,9 +148,9 @@
 
     elif os.name == "os2":
         if standard_lib:
-            return os.path.join(PREFIX, "Lib")
+            return os.path.join(prefix, "Lib")
         else:
-            return os.path.join(PREFIX, "Lib", "site-packages")
+            return os.path.join(prefix, "Lib", "site-packages")
 
     else:
         raise DistutilsPlatformError(
diff --git a/Lib/distutils/tests/test_sysconfig.py b/Lib/distutils/tests/test_sysconfig.py
index 4636c0c..dd17eb3 100644
--- a/Lib/distutils/tests/test_sysconfig.py
+++ b/Lib/distutils/tests/test_sysconfig.py
@@ -26,6 +26,8 @@
         # XXX doesn't work on Linux when Python was never installed before
         #self.assert_(os.path.isdir(lib_dir), lib_dir)
         # test for pythonxx.lib?
+        self.assertNotEqual(sysconfig.get_python_lib(),
+                            sysconfig.get_python_lib(prefix=TESTFN))
 
     def test_get_python_inc(self):
         inc_dir = sysconfig.get_python_inc()