Re: minor bug in babel with silent output and remote R session

[Thomas Alexander Gerds <tag@biostat.ku.dk>]

Hi Bastien

I think that I can describe the problem a bit better now. It is not
related to the silent option but occurs whenever ":results value".

Emacs freezes due to the following line in
org-babel-comint-eval-invisibly-and-wait-for-file 

(while (not (file-exists-p file)) (sit-for (or period 0.25)))

it seems that R cannot transfer the file and hence this is an endless
loop.

it may be possible to fix this using tramp, e.g. by setting the
default-directory in the buffer which runs the remote-session, or by
adding a more thorough check of whether the R-session is remote.

to this end let me note that there are at least two ways to start a
remote R session in emacs:

1) M-x shell
2) M-x ssh via ssh.el (not part of emacs)

Cheers 
Thomas


Bastien <bzg@gnu.org> writes:

> Hi Thomas,
>
> Thomas Alexander Gerds <tag@biostat.ku.dk> writes:
>
>> Using the silent option together with a remote R session block
>> (started via ssh.el and ess-remote), like this:
>> #+BEGIN_SRC R :results silent :exports results :session *ssh gauss*
>> :cache yes a=1 1 #+END_SRC
>> produces:
>> ,----
>> | > > > [1] 1 Warning message:
>> | In file.rename(tfile, transfer.file) : cannot rename file
>> | /tmp/RtmpQwlyCf/file7c9b78867f6c' to
>> | /tmp/babel-4977UIT/R-4977ucf', reason 'No such file or directory'
>> | >
>> `----
>> and emacs freezes. No big deal because C-g gets me out of it, but
>> slightly annoying.
>> with `:results output' instead of `:results: silent' everything
>> works fine.
>
> Please let us know if the documentation* needs some clarification
> here, or if this is a bug -- maybe someone will have time to look at
> it.
>
> Thanks,
>
> * Better to check against the latest documentation from our master
> branch, of course.
--
Thomas A. Gerds -- Assoc. Prof. Department of Biostatistics
University of Copenhagen, Øster Farimagsgade 5, 1014 Copenhagen, Denmark
Office: CSS-15.2.07 (Gamle Kommunehospital)
tel: 35327914 (sec: 35327901)