Sandro Romanzetti <roman.san...@gmail.com> writes: > Dear Tramp Developers,
Hi Sandro, > I am trying to execute the following R code from within a org-mode > file but it take more than 60 seconds to get the results back on my > screen. For this reason I usually login to my remote server and start > emacs from the terminal. In that case I have no delays whatsoever. > > Here is the source code block: > > #+begin_src R :session myplot :results value :colnames yes :exports results > library(tidyverse) > T<-tibble(x=(1:20),y=(1:20)) > T > #+end_src > > I attach the debug message (using tramp-verbose 10). I would be very grateful > if you could give me any hint on how to solve this issue. Thanks. I've tried to analyze the traces. Note that I don't use R, so I must guess something. The traces don't show any remote process call. So I assume that there is already a remote R process, running as REPL loop. The majority of the Tramp actions is about the remote file "/tmp/R-Gpow4E". It doesn't exist at the beginning, and Tramp marks it as such in the cache: --8<---------------cut here---------------start------------->8--- 00:52:36.548413 tramp-send-command (6) # test -e /tmp/R-Gpow4E 2>/dev/null; echo tramp_exit_status $? 00:52:36.591744 tramp-wait-for-regexp (6) # tramp_exit_status 1 ///1b9b06976240a21aa1381a07a40053bd#$ 00:52:36.591976 tramp-get-connection-property (7) # process-buffer nil; cache used: nil 00:52:36.592165 tramp-set-file-property (8) # /tmp/R-Gpow4E file-exists-p nil --8<---------------cut here---------------end--------------->8--- But then, your session waits that this file exists: --8<---------------cut here---------------start------------->8--- 00:52:36.876143 tramp-get-file-property (8) # /tmp/R-Gpow4E file-exists-p nil; inhibit: 60; cache used: t; cached at: 00:52:36 00:52:37.137672 tramp-get-file-property (8) # /tmp/R-Gpow4E file-exists-p nil; inhibit: 60; cache used: t; cached at: 00:52:36 [...] 00:53:36.565685 tramp-get-file-property (8) # /tmp/R-Gpow4E file-exists-p nil; inhibit: 60; cache used: t; cached at: 00:52:36 00:53:36.831883 tramp-get-file-property (8) # /tmp/R-Gpow4E file-exists-p undef; inhibit: 60; cache used: nil; cached at: 00:52:36 --8<---------------cut here---------------end--------------->8--- For 60 seconds, Tramp reports the non-existence according to its cache. Then the cache expires, and Tramp does a real check: --8<---------------cut here---------------start------------->8--- 00:53:36.881497 tramp-send-command (6) # test -e /tmp/R-Gpow4E 2>/dev/null; echo tramp_exit_status $? 00:53:36.930700 tramp-wait-for-regexp (6) # tramp_exit_status 0 ///1b9b06976240a21aa1381a07a40053bd#$ 00:53:36.931118 tramp-get-connection-property (7) # process-buffer nil; cache used: nil 00:53:36.931540 tramp-set-file-property (8) # /tmp/R-Gpow4E file-exists-p t --8<---------------cut here---------------end--------------->8--- Tramp knows about a stale cache when it starts a remote process. However, when a remote process is running, and a client program (your R session) sends statements which change the existence of a remote file, Tramp cannot know this. Your client program must inhibit Tramp's cache while doing so. I recommend you to contact the org maintainers about. At a proper place, where the code waits for the existence of the tmpfile, they shall let-bind remote-file-name-inhibit-cache to t. > Kind regards, > Sandro Romanzetti Best regards, Michael.
