Having trouble reproducing this. Here's one attempt:

from mercurial import demandimport
demandimport.enable()

import binascii

print binascii

from binascii import hexlify

print binascii

print hexlify

print binascii

$ python dl
<unloaded module 'binascii'>
<unloaded module 'binascii'>
<built-in function hexlify>
<unloaded module 'binascii'>