ob-async issue, seq-random-elt not defined

Question

I would like to asynchronously run code blocks in org mode.

My org mode version (org-version output) is: Org mode version 9.2.1 (9.2.1-23-g126a37-elpa @ /home/user/.emacs.d/elpa/org-9.2.2/)

I followed some instructions on this blog: http://cachestocaches.com/2018/6/org-literate-programming/

I installed ob-async.

I have a very simple Python code block in my org mode file:

#+BEGIN_SRC python :results output :async
import random
random.seed(1)
print("Hello World! Here's a random number: {}".format(random.random()))
#+END_SRC

#+RESULTS:
: f6d3fcf77d5cbec033f91b7dc23ebfe5

The result looks weird and every time I try to run the code block I see a messages in the messages buffer:

executing Python code block...
error in process sentinel: async-handle-result: Symbol’s value as variable is void: seq-random-elt
error in process sentinel: Symbol’s value as variable is void: seq-random-elt

I could not find anything helpful about this error so far.

How can I get asynchronous code execution from org source blocks to work properly?

Edit

I tried the following using emacs -Q startup:

In my *scratch* buffer I have the following content:

;; This buffer is for text that is not saved, and for Lisp evaluation.
;; To create a file, visit it with C-x C-f and enter text in its buffer.

(require 'package)
(package-initialize)
(require 'ob-async)

(setq org-babel-load-languages
      (quote
       ((emacs-lisp . t)
    (python . t)
    (scheme . t)
    (sh . t))))

Then I press C-j to evaluate. Then I open my .org file, which has the following source block and run the source block:

* Async Code Exec

Async package has issues and does not work?

#+BEGIN_SRC python :results output :async
import random
import time

random.seed(1)
time.sleep(5)
print("Hello World! Here's a random number: {}".format(random.random()))
#+END_SRC

#+RESULTS:
: Hello World! Here's a random number: 0.13436424411240122

The result is, that the time.sleep(5) blocks emacs and is not run asynchronously. However, at least the result is fine, even if that was not the main reason for creating this question.

The same blocking behavior happens when I try it with an elisp source block:

#+BEGIN_SRC elisp :results output :async
(progn (sleep-for 5) (print 1))
#+END_SRC

#+RESULTS:
: 
: 1

Edit 2

• My Emacs version is: GNU Emacs 25.2.2 (x86_64-pc-linux-gnu, GTK+ Version 3.22.21).

Edit 3

Running the following code also results in seq-random-elt being void error:

(async-start
   ;; What to do in the child process
   (lambda ()
     (message "This is a test")
     (sleep-for 3)
     222)

   ;; What to do when it finishes
   (lambda (result)
     (message "Async process done, result should be 222: %s" result)))

The error:

executing Elisp code block...
error in process sentinel: async-handle-result: Symbol’s value as variable is void: seq-random-elt
error in process sentinel: Symbol’s value as variable is void: seq-random-elt

Edit 4

Here is the issue on Github, which I created for the problem: https://github.com/astahlman/ob-async/issues/55

Edit 5

Sorry for asking this obviously bad question ...

Answer 1

I believe the answer is essentially that ob-async has a bug (either with how it implements this feature, or with its stated minimum supported verion of Emacs).

• The user is running Emacs 25.2.2
• seq-random-elt was introduced in Emacs 26
• ob-async states emacs-24.4 as its minimum requirement

Most likely this will be resolved upstream in https://github.com/astahlman/ob-async/issues/55