How to debug a transient (message) bug

[Dima Kogan]

Hi. I'm running a bleeding-edge build of emacs from git. Using X11 and
GTK.

Starting a month or two ago I'm observing a bug that's really annoying,
but I can't figure out how to reproduce it from an 'emacs -Q', or how to
debug it myself. Suggestions requested.

>From any emacs buffer I interactively hit M-! (shell-command), and
interactively give it a command that will produce some output; for
instance "seq 5". The expected output is

===========
1
2
3
4
5
===========

This produces the expected output in the *Shell Command Output* buffer,
and also pops up at the bottom of the frame because
(display-message-or-buffer) is called, which calls (message).

Usually I see this correct behavior. However, in my long-running emacs
sessions I reliably do NOT see this behavior if I M-! from a buffer
visiting a remote file via TRAMP. In this case, the output ends up in
*Shell Command Output* as it should and (message) is called as it
should. The (message) output does show up at the bottom of the frame,
but only instantaneously: as soon as it comes up, it goes away
immediately.

I cannot figure out why, and I don't know how to debug it. I'd like to
trace some sort of message-transient-buffer-go-away event, but I don't
know what that is. This is 100% reproducible and 100% annoying, so I'd
like to fix it. Any debugging suggestions?

Thanks