diff -r 32f0a519cc7a -r 2123324cca5a virtualenv/res/lib/lib_create_env.py
--- a/virtualenv/res/lib/lib_create_env.py	Thu Dec 13 17:43:48 2012 +0100
+++ b/virtualenv/res/lib/lib_create_env.py	Mon Dec 17 02:04:37 2012 +0100
@@ -319,6 +319,8 @@
                 method = install_options.get('method', default_install_options['method'])
                 option_str = install_options.get('option_str', default_install_options['option_str'])
                 extra_env = install_options.get('dict_extra_env', default_install_options['dict_extra_env'])
+                if 'TMPDIR' not in extra_env:
+                    extra_env['TMPDIR'] = tmp_dir          
                 #isinstance(lst, (list, tuple))
                 if key not in ignore_packages:
                     if callable(method):