This is like python-2.7.10-cross-distutils.patch, but we update the sysconfig
module instead of the distutils.sysconfig module.  Python ships two different
modules with strong overlap in functionality.

--- a/Lib/sysconfig.py
+++ b/Lib/sysconfig.py
@@ -7,10 +7,10 @@ from os.path import pardir, realpath
 
 _INSTALL_SCHEMES = {
     'posix_prefix': {
-        'stdlib': '{base}/@@GENTOO_LIBDIR@@/python{py_version_short}',
-        'platstdlib': '{platbase}/@@GENTOO_LIBDIR@@/python{py_version_short}',
-        'purelib': '{base}/@@GENTOO_LIBDIR@@/python{py_version_short}/site-packages',
-        'platlib': '{platbase}/@@GENTOO_LIBDIR@@/python{py_version_short}/site-packages',
+        'stdlib': '{base}/{libdirname}/python{py_version_short}',
+        'platstdlib': '{platbase}/{libdirname}/python{py_version_short}',
+        'purelib': '{base}/{libdirname}/python{py_version_short}/site-packages',
+        'platlib': '{platbase}/{libdirname}/python{py_version_short}/site-packages',
         'include': '{base}/include/python{py_version_short}',
         'platinclude': '{platbase}/include/python{py_version_short}',
         'scripts': '{base}/bin',
@@ -65,10 +65,10 @@ _INSTALL_SCHEMES = {
         'data'   : '{userbase}',
         },
     'posix_user': {
-        'stdlib': '{userbase}/@@GENTOO_LIBDIR@@/python{py_version_short}',
-        'platstdlib': '{userbase}/@@GENTOO_LIBDIR@@/python{py_version_short}',
-        'purelib': '{userbase}/@@GENTOO_LIBDIR@@/python{py_version_short}/site-packages',
-        'platlib': '{userbase}/@@GENTOO_LIBDIR@@/python{py_version_short}/site-packages',
+        'stdlib': '{userbase}/{libdirname}/python{py_version_short}',
+        'platstdlib': '{userbase}/{libdirname}/python{py_version_short}',
+        'purelib': '{userbase}/{libdirname}/python{py_version_short}/site-packages',
+        'platlib': '{userbase}/{libdirname}/python{py_version_short}/site-packages',
         'include': '{userbase}/include/python{py_version_short}',
         'scripts': '{userbase}/bin',
         'data'   : '{userbase}',
@@ -358,7 +358,16 @@ def _generate_posix_vars():
 def _init_posix(vars):
     """Initialize the module as appropriate for POSIX systems."""
     # _sysconfigdata is generated at build time, see _generate_posix_vars()
-    from _sysconfigdata import build_time_vars
+    if '_PYTHON_PROJECT_BASE' not in os.environ and os.getenv('SYSROOT'):
+        lib_dir = get_path('platstdlib')
+        sysconfig_path = os.path.join(lib_dir, '_sysconfigdata.py')
+        import imp
+        if not os.path.exists(sysconfig_path):
+            _, sysconfig_path, _ = imp.find_module('_sysconfigdata')
+        sysconfig_module = imp.load_source('_sysconfigdata', sysconfig_path)
+        build_time_vars = sysconfig_module.build_time_vars
+    else:
+        from _sysconfigdata import build_time_vars
     vars.update(build_time_vars)
 
 def _init_non_posix(vars):
@@ -471,7 +480,16 @@ def get_config_vars(*args):
         _CONFIG_VARS['base'] = _PREFIX
         _CONFIG_VARS['platbase'] = _EXEC_PREFIX
         _CONFIG_VARS['projectbase'] = _PROJECT_BASE
+        _CONFIG_VARS['srcdir'] = _PROJECT_BASE
 
+        libdir = None
+        if '_PYTHON_PROJECT_BASE' not in os.environ and os.getenv('SYSROOT'):
+            abi = os.getenv('ABI')
+            libdir = os.getenv('LIBDIR_%s' % abi)
+        if not libdir:
+            libdir = '@@GENTOO_LIBDIR@@'
+        _CONFIG_VARS['libdirname'] = libdir
+
         if os.name in ('nt', 'os2'):
             _init_non_posix(_CONFIG_VARS)
         if os.name == 'posix':
@@ -495,9 +513,6 @@
         # the init-function.
         _CONFIG_VARS['userbase'] = _getuserbase()
 
-        if 'srcdir' not in _CONFIG_VARS:
-            _CONFIG_VARS['srcdir'] = _PROJECT_BASE
-
         # Convert srcdir into an absolute path if it appears necessary.
         # Normally it is relative to the build directory.  However, during
         # testing, for example, we might be running a non-installed python