[ESS] Starting R

[Brett Presnell]

Today I installed a new version of ess from melpa and I find that I
cannot start R with the usual "M-x R RET" (if I type "M-x R <tab> the
completions R-mode, Rd-font Rd-mode, Rd-mode-insert-item,
Rd-mode-insert-section, Rd-mode-insert-skeleton, and Rd-preview-help are
offered, but not just plain R).

I am able to start R with "M-x ess-request-a-process".  I haven't gotten
much further than that, so I don't know if I will run into any other
problems.

This is on Ubuntu 20.04 with a snapshot of the current development
version of emacs:

GNU Emacs 28.0.50 (build 1, x86_64-pc-linux-gnu, GTK+ Version 3.24.20,
cairo version 1.16.0) of 2020-08-11

ess-version:  [elpa: 20200815.803] (loaded from /home/presnell/.emacs.d/elpa/ess-20200815.803/)


The problem persists if I start emacs with "-Q", put the ess package on
the load-path, and load ess-site.el.

Obviously the emacs version may have something to do with this.

Any ideas?