diff -r f36d8ba4eeef Lib/tempfile.py
--- a/Lib/tempfile.py	Sat Feb 09 12:21:52 2013 +0200
+++ b/Lib/tempfile.py	Sat Feb 09 16:31:54 2013 +0200
@@ -31,6 +31,7 @@
 import sys as _sys
 import io as _io
 import os as _os
+import errno as _errno
 from random import Random as _Random
 
 try:
@@ -181,7 +182,9 @@
                 pass
             except OSError:
                 break   # no point trying more names in this directory
-    raise FileNotFoundError("No usable temporary directory found in %s" % dirlist)
+    raise FileNotFoundError(_errno.ENOENT,
+                            "No usable temporary directory found in %s" %
+                            dirlist)
 
 _name_sequence = None
 
@@ -214,7 +217,8 @@
         except FileExistsError:
             continue    # try again
 
-    raise FileExistsError("No usable temporary file name found")
+    raise FileExistsError(_errno.EEXIST,
+                          "No usable temporary file name found")
 
 
 # User visible interfaces.
@@ -301,7 +305,8 @@
         except FileExistsError:
             continue    # try again
 
-    raise FileExistsError("No usable temporary directory name found")
+    raise FileExistsError(_errno.EEXIST,
+                          "No usable temporary directory name found")
 
 def mktemp(suffix="", prefix=template, dir=None):
     """User-callable function to return a unique temporary file name.  The
@@ -330,7 +335,8 @@
         if not _exists(file):
             return file
 
-    raise FileExistsError("No usable temporary filename found")
+    raise FileExistsError(_errno.EEXIST,
+                          "No usable temporary filename found")
 
 
 class _TemporaryFileWrapper: