jupyter-session-with-random-ports: ‘jupyter kernel‘ failed to show connection file path

[simenojensen]

I updated jupyter using conda, and then C-c C-p (jupyter-run-repl) no longer worked

error message:
jupyter-session-with-random-ports: ‘jupyter kernel‘ failed to show connection file path

The below code which redefines the function fixes the problem

  (defun jupyter-session-with-random-ports ()
    "Return a `jupyter-session' with random channel ports."
    (with-temp-buffer
      (let* ((j (or (executable-find "jupyter")
                    (error "Cannot find `jupyter` executable")))
             (process
              (if (file-remote-p default-directory)
                  ;; Remote: still use start-file-process so TRAMP works
                  (start-file-process
                   "jupyter-session-with-random-ports" (current-buffer)
                   j "kernel")
                ;; Local: capture stderr too
                (make-process
                 :name "jupyter-session-with-random-ports"
                 :buffer (current-buffer)
                 :command (list j "kernel")
                 :stderr (current-buffer)
                 :noquery t))))
        (set-process-query-on-exit-flag process nil)

        (let ((conn-path nil)
              (deadline (+ (float-time) jupyter-long-timeout)))
          (while (and (process-live-p process)
                      (not conn-path)
                      (< (float-time) deadline))
            (accept-process-output process 0.05)
            (save-excursion
              (goto-char (point-min))
              (when (re-search-forward
                     (rx "Connection file:" (* space)
                         (group "/" (+ (not (any "\n\r"))) ".json"))
                     nil t)
                (setq conn-path (match-string 1)))))

          (unless conn-path
            (let ((out (buffer-string)))
              (when (process-live-p process) (delete-process process))
              (error "`jupyter kernel` did not print a parsable connection file path. Captured output:\n%s"
                     (if (> (length out) 4000) (substring out 0 4000) out))))

          (let* ((conn-file (concat
                             (save-match-data (file-remote-p default-directory))
                             conn-path))
                 (conn-info (jupyter-read-connection conn-file)))
            ;; shut down kernel
            (interrupt-process process)

            ;; wait for connection file cleanup
            (jupyter-with-timeout
                (nil (if (file-remote-p conn-file) 0 jupyter-default-timeout)
                     (delete-file conn-file))
              (not (file-exists-p conn-file)))

            (delete-process process)

            (let ((new-key (jupyter-new-uuid)))
              (plist-put conn-info :key new-key)
              (jupyter-session :conn-info conn-info :key new-key)))))))