The following code crashes when ran on Django==1.5, but it works fine on Django==1.4.3. (Both py27.)

log.txt

$ python minimal_example.py
Traceback (most recent call last):
  File "minimal_example.py", line 7, in <module>
    s.sign('foo')
  File "/Users/nvie/.virtualenvs/foo/lib/python2.7/site-packages/django/core/signing.py", line 175, in sign
    return str('%s%s%s') % (value, self.sep, self.signature(value))
  File "/Users/nvie/.virtualenvs/foo/lib/python2.7/site-packages/django/core/signing.py", line 169, in signature
    signature = base64_hmac(self.salt + 'signer', value, self.key)
  File "/Users/nvie/.virtualenvs/foo/lib/python2.7/site-packages/django/core/signing.py", line 75, in base64_hmac
    return b64_encode(salted_hmac(salt, value, key).digest())
  File "/Users/nvie/.virtualenvs/foo/lib/python2.7/site-packages/django/utils/crypto.py", line 48, in salted_hmac
    key = hashlib.sha1((key_salt + secret).encode('utf-8')).digest()
UnicodeDecodeError: 'ascii' codec can't decode byte 0xe7 in position 0: ordinal not in range(128)

minimal_example.py

from django.conf import settings
from django.core.signing import Signer

settings.SECRET_KEY = b'\xe7'  # binary key with non-ASCII chars

s = Signer()
print(s.sign('foo'))