Tweak the source block indentation options

README.org

@@ -2493,7 +2493,9 @@ When called twice, replace the previously inserted \\(\\) by one $."
 #+begin_src emacs-lisp -n
 (with-eval-after-load 'emacs
   (with-eval-after-load 'org-src
-    (setopt org-src-preserve-indentation t)
+    ;; https://list.orgmode.org/c3cc4ff1fcfb3bc741df89a3f45be30e@posteo.net/
+    (setopt org-src-preserve-indentation nil
+            org-edit-src-content-indentation 0)
 
     (defun org-left-shift-block ()
       "Left-shift the block at point using `org-indent-block'."
@@ -3714,23 +3716,20 @@ facilities for [[https://orgmode.org/worg/org-tests/index.html][Testing Org]].
                (file-name-directory
                 (buffer-file-name (get-buffer "org.el")))))
              (file-name-as-directory "testing")))
-      (message "`%s'" org-testing-dir)
       (setq org-testing-lisp-files
             (seq-filter
              (lambda (f)
                (string-suffix-p ".el" f))
              (directory-files
               (file-name-concat org-testing-dir
-                                (file-name-as-directory "lisp")))))
-      (message "`%s'" org-testing-lisp-files))
+                                (file-name-as-directory "lisp"))))))
     (unless (fboundp 'org-test-with-temp-text)
       (find-file (file-name-concat org-testing-dir "org-test.el"))
       (eval-buffer)
       (quit-window))
     (let* ((test
             (completing-read "Org-mode test: "
-                             org-testing-lisp-files nil 'require-match))
-           (file ))
+                             org-testing-lisp-files nil 'require-match)))
       (find-file (file-name-concat
                   org-testing-dir (file-name-as-directory "lisp") test))
       (eval-buffer)