How to execute org-mode source block asynchronously in session?

Question

I have an org file with notes about how to setup my project. One of the notes has some shell scripts, like this:

#+begin_src sh :dir ~/Workspace/MyProject :session cmake-setup
cmake -B build-debug -S . -G Ninja \
  -DCMAKE_EXPORT_COMPILE_COMMANDS=ON -DCMAKE_BUILD_TYPE=Debug
#+end_src

I can hit C-c C-c there and execute the shell command. But the problem is that Emacs hangs for 5-10 seconds while that command runs. When it's done I can switch to the cmake-setup buffer and see the output. But I'd like to switch to the shell buffer right away and see the progress. This will be essential when commands take more than a few seconds.

I found ob-async and added the :async header to the source block. It stops freezing emacs, but it ignores the :session header and puts the huge amount of output into my org file.

Is there a way to make my code block execute asynchronously and keep it running in the session?

Answer 1

I guess a slightly belated response, but you can do this at the org-babel level as well. The ob-async package does not support the :session header, but ob-session-async does and it was merged into the standard library as of Org 9.5. So in theory, :async :session cmake-setup should do what you want with Org >= 9.5 even if you don't move your cmake command to the background with &.