cross-compilation support for python build

Lib/packaging/tests/support.py

 """Support code for packaging test cases.
 
 *This module should not be considered public: its content and API may
 change in incompatible ways.*
 
 A few helper classes are provided: LoggingCatcher, TempdirManager and
 EnvironRestorer. They are written to be used as mixins::
 
     from packaging.tests import unittest
     from packaging.tests.support import LoggingCatcher
@@ skipping 321 matching lines @@
     the test will be skipped.  Errors during copy are not caught.
     """
     filename = _get_xxmodule_path()
     if filename is None:
         raise unittest.SkipTest('cannot find xxmodule.c')
     shutil.copy(filename, directory)
 
 
 def _get_xxmodule_path():
     if sysconfig.is_python_build():
-        srcdir = sysconfig.get_config_var('projectbase')
+        srcdir = sysconfig.get_config_var('srcdir')
         path = os.path.join(os.getcwd(), srcdir, 'Modules', 'xxmodule.c')
     else:
         path = os.path.join(os.path.dirname(__file__), 'xxmodule.c')
     if os.path.exists(path):
         return path
 
 
 def fixup_build_ext(cmd):
     """Function needed to make build_ext tests pass.
 
@@ skipping 38 matching lines @@
 
 
 try:
     from test.support import skip_unless_symlink
 except ImportError:
     skip_unless_symlink = unittest.skip(
         'requires test.support.skip_unless_symlink')
 
 skip_2to3_optimize = unittest.skipIf(sys.flags.optimize,
                                      "2to3 doesn't work under -O")