Checked out the PY3K branch and built. Received a warning 
about "characters after #ifdef ignored" from Objects/stringlib/find.h

the line in question is:

#ifdef STRINGLIB_WANT_CONTAINS_OBJ && !defined(FROM_BYTEARRAY)

Which is likely to mean that it will not do what is expected.

System is Ubuntu using GCC (otoh can't remember full compiler spec will 
post in later)

Patch to follow that modifies the above line to:

#if defined(STRINGLIB_WANT_CONTAINS_OBJ) && !defined(FROM_BYTEARRAY)

and will change the comment on the closing #endif too.

hope component choice is correct