[sorry if this is not the correct bug format, I'm replying to a message
on gnu.emacs.help]

* Eli Zaretskii <mailman.985.1562918079.2688.help-gnu-emacs@gnu.org> :
Wrote on Fri, 12 Jul 2019 10:54:28 +0300:

>> Date: 12 Jul 2019 06:20:57 -0000
>> From: Madhu <enometh@meer.net>
>>
>> Earlier it used to be possible to gdb attach to the emacs process and
>> to restart the server. Something like
>> Feval(Fcar(Fread_from_string(build_string("(server-start)"),Qnil,Qnil)),Qnil)
>> But for some time now that route hits a
>> terminate_due_to_signal. (Apparently make-network-process tries to
>> signal an error which calls emacs_abort which ends the show)
>
> Please report a bug with the details of that crash, it may or may not
> be a bug.

I noticed a couple of different failure modes but this problem seems to
be related to pselect.  I'm appending one backtrace. Note within the
transcript emacs is started with

args:  -Q --eval '(progn (load-library "custom") (load-library "server") (setq server-name "emacs-test"))'

After emacs is started by gdb I send it a TSTP to make it enter the
debugger.