[ESS] ESS failing to load from a directory outside the FHS

[Steve Gutreuter]

I have been unable to get ESS to load into Emacs on a CentOS7 compute 
server on which software is installed in locations that are not part of 
the FHS.

Lines 99 and 100 of my .emacs file contain:

(add-to-list 'load-path "/apps/x86_64/emacs/ess-18.10.2/lisp/")
(require 'ess-site)

A full byte-compiled ESS installation exists in 
apps/x86_64/emacs/ess-18.10.2. I have tried with and without the final 
~lisp/, but neither works.

When byte-compiling my .emacs I get the following two related (I think) 
messages.  In the *Messages* buffer I get:

ERROR:ess-etc-directory
Relative to ess-lisp-directory, one of the following must exist:
../etc/ess, ../etc, ../../etc/ess or ./etc

And in the *Compile-log* buffer I get:

Compiling file /scicomp/home-pure/wqh4/.emacs at Wed Mar 17 08:25:49 2021
.emacs:100:1:Error: Cannot open load file: No such file or directory, 
ess-rd.el

Note that line 100 in .emacs contains (require 'ess-site). Further, both 
ess.rd.el and ess.rd.elc exist in /apps/x86_64/emacs/ess-18.10.2/lisp/ 
and I have read+write permissions on that directory.

So it *looks* like /apps/x86_64/emacs/ess-18.10.2/lisp/ is not actually 
being added to the load path.  Any tips?

Thanks in advance.

-- 
Steve Gutreuter