Emacs server/emacsclient won't connect

Question

I just installed Ubuntu 18.04 and GNU Emacs 26.1 (build 2, x86_64-pc-linux-gnu, GTK+ Version 3.22.30) on my Lenovo W541 laptop. Under this new installation, the emacs server & emacsclient functionality no longer works. Invoking "emacsclient" at the command prompt tells me

emacsclient: can't find socket; have you started the server?
To start the server in Emacs, type "M-x server-start".

But when I try to server-start in emacs,

‘server-start’ is an obsolete command; use ‘gnuserv-start’ instead.
Server subprocess exited
You can run the command ‘server-start’ with M-x ser-s RET
Server subprocess exited

Is the solution just to (as suggested) install gnuserv instead?

UPDATE 1 In response to @waltinator 's suggestion, I enter ^H+f server-start and get the response:

server-start is an interactive autoloaded Lisp function in
‘server.el’.
(server-start &optional LEAVE-DEAD)
This function is obsolete;
use ‘gnuserv-start’ instead.
Use ‘gnuserv-start’ instead of this function.
Allow this Emacs process to be a server for client processes.
This starts a server communications subprocess through which
client "editors" can send your editing commands to this Emacs job.
To use the server, set up the program ‘emacsclient’ in the
Emacs distribution as your standard "editor".
--
Prefix arg means just kill any existing server communications subprocess.

But there is still no match for 'gnuserv-start', nor is it clear online how to install it (pages typically note that it should come installed with Emacs). Thoughts?

Answer 1

It turned out that the solution was to put the following lines in my .emacs startup file:

(autoload 'gnuserv-start "gnuserv-compat"
         "Allow this Emacs process to be a server for client   processes."
         t)
(gnuserv-start)
(setq gnuserv-frame (selected-frame))

Then 'gnuclient filename &' opens 'filename' right into the main emacs buffer. Strange that 'emacsclient' no longer works, but... there you have it.