bug#50514: 28.0.50; org inline call to python src block req C-g to break

[Ihor Radchenko]

Lars Ingebrigtsen <larsi@gnus.org> writes:

>> Could you please elaborate what the problem is?
>> There have been multiple issues in this thread and the one previously
>> reported to Org ML is solved on Emacs side.
>
> It's this bit:
>
>> So I found if I extend the sleep-for in ob-python from 10 ms to 90 ms,
>> my initialization problem is “fixed”.
>
> The sleep is still 10ms in the in-tree ob-python, at least.

10ms magic constant is indeed not great.
However, I am unable to reproduce the original bug on my system.
I tried to draft an alternative patch. See the attached.

Mark, would you mind testing the patch?

-- 
Ihor Radchenko,
Org mode contributor,
Learn more about Org mode at https://orgmode.org/.
Support Org development at https://liberapay.com/org-mode,
or support my work at https://liberapay.com/yantar92


>From d5347c688d2fb8037116d82fa7987e9e6690ae66 Mon Sep 17 00:00:00 2001
Message-Id: 
<d5347c688d2fb8037116d82fa7987e9e6690ae66.1661609451.git.yantar92@gmail.com>
From: Ihor Radchenko <yantar92@gmail.com>
Date: Sat, 27 Aug 2022 22:06:11 +0800
Subject: [PATCH] ob-python: Fix Emacs bug#50514 when Python loads slowly

* lisp/ob-python.el (org-babel-python-initiate-session): Wait until
python process is initialized.
(org-babel-python-initiate-session-by-key): Do not rely on 10ms delay
to initialize Python.
---
 lisp/ob-python.el | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/lisp/ob-python.el b/lisp/ob-python.el
index 932aca08e..2ad907bd8 100644
--- a/lisp/ob-python.el
+++ b/lisp/ob-python.el
@@ -197,8 +197,7 @@ (defun org-babel-python-initiate-session-by-key (&optional 
session)
          (setq py-buffer (org-babel-python-with-earmuffs session)))
        (let ((python-shell-buffer-name
               (org-babel-python-without-earmuffs py-buffer)))
-         (run-python cmd)
-         (sleep-for 0 10)))
+         (run-python cmd)))
        ((and (eq 'python-mode org-babel-python-mode)
             (fboundp 'py-shell)) ; python-mode.el
        (require 'python-mode)
@@ -225,8 +224,9 @@ (defun org-babel-python-initiate-session-by-key (&optional 
session)
 (defun org-babel-python-initiate-session (&optional session _params)
   "Create a session named SESSION according to PARAMS."
   (unless (string= session "none")
-    (org-babel-python-session-buffer
-     (org-babel-python-initiate-session-by-key session))))
+    (let ((session (org-babel-python-session-buffer
+                    (org-babel-python-initiate-session-by-key session)))))
+    (org-babel-comint-wait-for-output session)))
 
 (defvar org-babel-python-eoe-indicator "org_babel_python_eoe"
   "A string to indicate that evaluation has completed.")
-- 
2.35.1