>> What's the appropriate bludgeon and where do I apply it to convince
>> sshd that I do in fact know what I'm doing, and it should do X
>> forwarding?
> Well, according to the man page for sshd_config you should adjust the
> XAuthLocation option.

!!  Jeremy Reed pointed out its presence in ssh_config, where it
doesn't matter.  I didn't look for it in sshd_config(5) because the
comments in sshd_config say that

# The strategy used for options in the default sshd_config shipped with
# OpenSSH is to specify options with their default value where
# possible, but leave them commented.  Uncommented options change a
# default value.

and it isn't there.

Thanks for the cluesticking.  Is it perhaps worth a PR that it's not
present in sshd_config?

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