Hi Michael -
Got back to this.
Good news! The patch for compile.el, applied to Emacs 27.1, fixes the issue of the tramp window hanging in my test cases, running tramp from MAC.
There is still one tramp hanging issue I saw in my testing. This is a much less serious issue (pressing ctrl-G once "unhangs"), but thought I'd mention it here. LMK if you'd prefer a separate bug report and I'll create one.
If, during a "make" via tramp with many syntax errors, you click on one of the early errors produced in the tramp window, the compile pauses and the source window does not move to the error. Emacs appears to hang.
If you press ctrl-G, then the compile continues, no problem, until eventually exiting.
I also noticed the same effect if I just try and type a few characters into the source file while the make is going on - the compile hangs, and emacs appears to hang, until I press ctrl-G to allow it to continue.
When I perform this operation directly in emacs on the ubuntu machine (i.e. without using tramp), clicking on an early error message while "make" continues to run does not hang anything - the "make" process continues and meanwhile (even before make completes) the source window moves to the error that I clicked on. Likewise I can type characters into the test.cpp source file during make without causing a hang.
I am enclosing another test.cpp with even more errors to make it easier to catch this issue (you can just drop it into the src directory you were using for the last setup, overwriting the prior test.cpp).
By the way, this time, the issue reproduces for me regardless of whether I am running the emacs-tramp on a Mac or on an ubuntu client; as you'll recall, the target host is ubuntu in both cases.
Thanks again for fixing the main hanging issue!
Duncan.
Duncan Greatwood <dgbulk@gmail.com> writes:
Hi Duncan,
> Meanwhile, good luck with debugging these bug#45518 issues.
Finally, I nailed it down. In the (remote) compilation process, there is
a process filter, which calls `file-truename' if it detects an
error. This works one or two times, but then the (remote) compilation
process comes in conflict with the (remote) Tramp process responsible
for `file-truename'.
The following patch has fixed the issue for me on my FreeBSD machine. It
is on top of Emacs' git master; but likely it works also for your Emacs
27 (not tested by me). Could you check, whether this helps you?
> Thanks again!
Best regards, Michael.