[ESS-bugs] new iESS bug "Symbol's value as variable is void: resume"

[Martin Maechler]

This happens only since this morning,
I don't see yet how to make it entirely reproducible,

but I now have encountered it *twice* within 20 minutes:
Both however, only relatively immediately after starting a new R
process:

M-x R  and I work in the *R* buffer,

Type things like

  require("Rmpfr")
and
  (a <- ......) 

Then, after my typing of [Enter],
*instead* of the corresponding line being evaluated by R,
it is *NOT* evaluated, and in the minibuffer I get the error message

Symbol's value as variable is void: resume

In the *R* buffer, I get an extra newline and a new prompt.
If I do the same thing a second time,
it works.