Python 3.3 + Cython 20.1 build failure

[popham]

I've got a failing build on an Archlinux 64-bit box with Python3.3 installed from source:

    Error compiling Cython file:
    ------------------------------------------------------------
    ...
            :Exceptions:
                - `ValueError`: The value could not be parsed.
            """
            cdef sockaddr_in * sin
            cdef sockaddr_in6 *sin6
            cdef sockaddr_un * sun
                ^
    ------------------------------------------------------------

    coro/socket.pyx:990:13: 'sockaddr_un' is not a type identifier

I've traced the problem to the Cython compiler comparing UNAME_SYSNAME against "Linux" with one encoded as bytes and the other as a unicode string in socket.pxd:

    cdef extern from "sys/un.h":
        IF UNAME_SYSNAME == "Linux":  # I'm broken
            cdef struct sockaddr_un:
                short sun_family
                char sun_path[104]
        ELSE:
            pass

I'm not sure if this is a bug here or upstream. I think the official Cython string philosophy may require a -3 flag to the Cython build in my use-case.

[markpeek]

I looked at this a little bit over the weekend. While I can get past the above issue with:
IF UNAME_SYSNAME == u"Linux":
it really is the more general issue of support Python 3.x. I'm going to talk with some of the other committers to see what we can do to support it.

[cjrh]

Seems like #76 is a duplicate of this.