[ts-gen] MacOS Shim problems

[Bill Pippin]

Ric,

About your problems getting the shim running on a Mac, first I'll try
to summarize what I understand from your reports to date:

    1.  There are problems with network configuration for IPv6.
    2.  There seem to be other problems as well; once the shim starts
        up properly, the shim seems to hang.  More precisely, you are
        not able to enter commands, or they are being ignored.

I'm not sure from the information I have so far exactly what is
causing the problems you are seeing.  I've decided to split my
reply, then, into two posts, the first for the case where network
configuration is not a cause for the hang you see, and the second
where it is.

I hope you'll read and consider both posts before you commit to a
debugging approach, since if the hang is not platform related, I
find the exact symptoms you've reported baffling, and I'm not sure
how exactly the problem should be fixed; and if it is, I can't
test proposed fixes, and again, it's hard to be sure some candidate
fix attacks the real problem.

In brief, much of my next post will describe shim features that you
can use to trace IO operations by the shim, while its successor will
consider possible issues with the network socket code in lib/inet.c .

Again, I suggest that you consider *both* of the following posts that
I'm sending to you, and please let us know what you results you see.

Thanks,

Bill