Index: setup.py
===================================================================
--- setup.py	(révision 83978)
+++ setup.py	(copie de travail)
@@ -22,6 +22,10 @@
 # This global variable is used to hold the list of modules to be disabled.
 disabled_module_list = []
 
+# File which contains the directory for shared mods (for sys.path fixup
+# when running from the build dir, see Modules/getpath.c)
+_BUILDDIR_COOKIE = "pybuilddir.txt"
+
 def add_dir_to_list(dirlist, dir):
     """Add the directory 'dir' to the list 'dirlist' (at the front) if
     1) 'dir' is not already in 'dirlist'
@@ -255,6 +259,11 @@
             print_three_column(failed)
             print()
 
+        import locale
+        with open(_BUILDDIR_COOKIE, "wb") as f:
+            f.write(self.build_lib.encode(locale.getpreferredencoding(),
+                                          'surrogateescape'))
+
     def build_extension(self, ext):
 
         if ext.name == '_ctypes':
Index: Lib/site.py
===================================================================
--- Lib/site.py	(révision 83978)
+++ Lib/site.py	(copie de travail)
@@ -107,19 +107,7 @@
     sys.path[:] = L
     return known_paths
 
-# XXX This should not be part of site.py, since it is needed even when
-# using the -S option for Python.  See http://www.python.org/sf/586680
-def addbuilddir():
-    """Append ./build/lib.<platform> in case we're running in the build dir
-    (especially for Guido :-)"""
-    from sysconfig import get_platform
-    s = "build/lib.%s-%.3s" % (get_platform(), sys.version)
-    if hasattr(sys, 'gettotalrefcount'):
-        s += '-pydebug'
-    s = os.path.join(os.path.dirname(sys.path.pop()), s)
-    sys.path.append(s)
 
-
 def _init_pathinfo():
     """Return a set containing all existing directory entries from sys.path"""
     d = set()
@@ -529,9 +517,6 @@
 
     abs_paths()
     known_paths = removeduppaths()
-    if (os.name == "posix" and sys.path and
-        os.path.basename(sys.path[-1]) == "Modules"):
-        addbuilddir()
     if ENABLE_USER_SITE is None:
         ENABLE_USER_SITE = check_enableusersite()
     known_paths = addusersitepackages(known_paths)
Index: Modules/getpath.c
===================================================================
--- Modules/getpath.c	(révision 83978)
+++ Modules/getpath.c	(copie de travail)
@@ -131,6 +131,10 @@
 static wchar_t *module_search_path = NULL;
 static wchar_t *lib_python = L"lib/python" VERSION;
 
+/* Defined in Modules/main.c */
+extern wchar_t* _Py_char2wchar(char* arg);
+extern FILE *_Py_wfopen(const wchar_t *path, const wchar_t *mode);
+
 /* In principle, this should use HAVE__WSTAT, and _wstat
    should be detected by autoconf. However, no current
    POSIX system provides that function, so testing for
@@ -396,10 +400,26 @@
 
     /* Check to see if argv[0] is in the build directory */
     wcscpy(exec_prefix, argv0_path);
-    joinpath(exec_prefix, L"Modules/Setup");
+    joinpath(exec_prefix, L"pybuilddir.txt");
     if (isfile(exec_prefix)) {
-        reduce(exec_prefix);
-        return -1;
+        FILE *f = _Py_wfopen(exec_prefix, L"rb");
+        if (f == NULL)
+            errno = 0;
+        else {
+            char buf[MAXPATHLEN+1];
+            wchar_t *rel_builddir_path;
+            size_t n;
+            n = fread(buf, 1, MAXPATHLEN, f);
+            buf[n] = '\0';
+            fclose(f);
+            rel_builddir_path = _Py_char2wchar(buf);
+            if (rel_builddir_path != NULL) {
+                wcscpy(exec_prefix, argv0_path);
+                joinpath(exec_prefix, rel_builddir_path);
+                PyMem_Free(rel_builddir_path);
+                return -1;
+            }
+        }
     }
 
     /* Search from argv0_path, until root is found */
Index: Modules/main.c
===================================================================
--- Modules/main.c	(révision 83978)
+++ Modules/main.c	(copie de travail)
@@ -101,10 +101,10 @@
 PYTHONIOENCODING: Encoding[:errors] used for stdin/stdout/stderr.\n\
 ";
 
+FILE *
+_Py_wfopen(const wchar_t *path, const wchar_t *mode)
+{
 #ifndef MS_WINDOWS
-static FILE*
-_wfopen(const wchar_t *path, const wchar_t *mode)
-{
     char cpath[PATH_MAX];
     char cmode[10];
     size_t r;
@@ -119,8 +119,10 @@
         return NULL;
     }
     return fopen(cpath, cmode);
+#else
+    return _wfopen(path, mode);
+#endif
 }
-#endif
 
 
 static int
@@ -640,7 +642,7 @@
         }
 
         if (sts==-1 && filename!=NULL) {
-            if ((fp = _wfopen(filename, L"r")) == NULL) {
+            if ((fp = _Py_wfopen(filename, L"r")) == NULL) {
                 char cfilename[PATH_MAX];
                 size_t r = wcstombs(cfilename, filename, PATH_MAX);
                 if (r == PATH_MAX)