Hi, thanks, that's what I had expected since that patch has been around for a long time. I run emacs -q --load /tmp/init.el --file=/tmp/test.org with my /tmp/init.el being only > (require 'package) > (package-initialize) > (add-to-list 'load-path "~/.emacs.d/straight/repos/org/lisp/") > (require 'org) > > ;(require 'ess-site) > (org-babel-do-load-languages > 'org-babel-load-languages > '((R . t))) I hope this constitutes a minimal example for a config - please correct me if I'm wrong. My test.org contains the source block I had already posted: #+begin_src R :results output :session *R* :exports both a <- 10 a #+end_src Any ideas how I could continue to debug this? If I just remove that patch, everything works flawlessly for me but I would like to figure out what causes the issues. Thanks! Christian On Sun, 2022-05-15 at 16:08 +0800, Ihor Radchenko wrote: > Christian Heinrich writes: > > > I got back to an org file after upgrading to the latest release of org-mode and tried executing > > the > > contained R source blocks. Unfortunately, emacs got stuck in the execution and was blocked; I > > had to > > exit using C-g. > > > > Here's a minimal example src block that causes emacs to get stuck: > > > > #+begin_src R :results output :session *R* :exports both > >   a <- 10 > >   a > > #+end_src > > > > R itself does start and the code is also executed correctly. However, the output from that > > session > > is apparently not returned to emacs or the buffer. > > I tried you example using Emacs >=26 and it works just fine. > > Best, > Ihor