bug#43888: 28.0.50; emacsclient not working properly

[Eli Zaretskii]

> From: Michael Heerdegen <michael_heerdegen@web.de>
> Cc: Gábor <hajovonta@gmail.com>,  larsi@gnus.org,
>   npostavs@gmail.com,
>   43888@debbugs.gnu.org
> Date: Mon, 12 Oct 2020 07:58:27 +0200
> 
> Eli Zaretskii <eliz@gnu.org> writes:
> 
> > > *ERROR*: Wrong number of arguments: (1 . 4), 5
> 
> > But since with "emacs -Q" it does work, it is still some of your
> > customizations that are the prime suspect.
> 
> Is there a way for the user to get an error message more verbose than
> above?

Yes, make sure debug-on-signal and debug-on-error are both non-nil in
the Emacs that runs the server, then you will have the backtrace pop
up in Emacs.  Assuming there's some frame visible for the server, that
is.