bug#45518: Ctrl-G Fails to Interrupt Hung Tramp Remote-Compile in Emacs 27.1

[Michael Albinus]

Duncan Greatwood <dgbulk@gmail.com> writes:

> Hi Michael -

Hi Duncan,

> Is there a way for me to capture any trace, call-stack or similar when
> the emacs window is in the tramp-hung state? I could share that back
> to you, if practical.

Good News: I have a FreeBSD 12.1 VM hanging around. Installing Emacs 28
on that machine, trying your recipe with my remote Ubuntu machine, and
voilà - it hangs. Great :-)

Well, C-g several times doesn't kill the compile process, but so what: I
can test now. Will play with this next days, as time permits.

> Alternatively, if you had time and could spend the few $s (it's "pay
> as you go"), you could try from a Mac on Amazon.
> https://aws.amazon.com/ec2/instance-types/mac/

Ah, I didn't know. Good to have it as fallback, I don't care to share
some few $s ...  But I haven't used this type of OS ever, so I would
need to learn how to install Emacs there.

> Finally, presuming we can't fix the underlying issue on mac, do you
> know approximately when the version of tramp that fixes the "Ctrl-G x3
> Fails to Interrupt Hung Tramp" issue will make it to release? The
> December 29th version I tried coupled with emacs 27.1 seemed to fix
> the ctrl-g issue but otherwise was quite inclined to crash-and-exit
> emacs. I know the tramp version I tried is an alpha so no problem,
> just wondering when it may reach general release?

It is Tramp 2.5.0, which I have released meanwhile via GNU ELPA. So you
might try to install it from there. Emacs 28, which will carry it
built-in, is still months away from a release. I wouldn't even bet that
this will happen this year; currently Emacs 27.2 has started its
pretest. However, I plan regular Tramp 2.5 releases via GNU ELPA (once a
month or so).

What do you mean with "crash-and-exit emacs"? Is it just because of the
changed Tramp version?

There have been bug reports that Tramp could crash Emacs on macOS. But
finally, it wasn't a Tramp issue, but rather a bug in Emacs which was
uncovered by Tramp. This is fixed now in the Emacs repository, see
bug#24472, bug#37299, bug#37557. The bugs are merged, so it seems to be
the same problem.

If you see other problems related to Tramp 2.5.0, pls report. I'll
happily try to fix them.

> Regards,
> Duncan.

Best regards, Michael.