[ESS] ESS sets options(editor="gnuclient.exe") , but gnuclient.exe fails to run.

[Josh O'Brien]

Hello,

During package development, I often use trace("foofun", edit=TRUE) to
test small code edits without having to reinstall the entire package.
This should launch the editor pointed to by options("editor"), which
is set by ESS to options(editor="gnuclient.exe"). (The responsible
code seems to be in lines 1396-1402 of ess-custom.el)

When I try to use trace() like this, though, I get the following error:

>  trace("mean", edit=TRUE)
# Error in edit(name, file, title, editor) :
#   unable to run editor 'gnuclient.exe'

I am using R-2.14.2 for Windows, Vincent Goulet's Windows bundle of
Emacs 23.3, and ESS 12.09.
My R executables are stored under C:/R/, and I point to them using this:

(setq ess-directory-containing-R "c:")
(load "ess-site")

How might I fix this?  Do I need to download and install
gnuclient.exe, or point to another editor (which?), or something else?
Also, might this be happening because I run R from a non-standard
folder?

Please let me know if other details of my setup might help in diagnosing this.

Thanks,

Josh O'Brien