How to debug and fix emacs progn: WakaTime Error (2)

Error message

The emacs plugin wakatime shows the following error message when save file each time.

error in process sentinel: progn: WakaTime Error (2)
error in process sentinel: WakaTime Error (2)
error in process sentinel: progn: WakaTime Error (2)
error in process sentinel: WakaTime Error (2)

Debug

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The *backtrace* content

Debugger entered--Lisp error: (error "WakaTime Error (2)")
  signal(error ("WakaTime Error (2)"))
  error("WakaTime Error (%s)" 2)
  (progn (error "WakaTime Error (%s)" exit-status))
  (if (and (not (= 0 exit-status)) (not (= 102 exit-status))) (progn (error "WakaTime Error (%s)" exit-status)))
  (when (and (not (= 0 exit-status)) (not (= 102 exit-status))) (error "WakaTime Error (%s)" exit-status))
  (let ((exit-status (process-exit-status process))) (when (and (not (= 0 exit-status)) (not (= 102 exit-status))) (error "WakaTime Error (%s)" exit-status)) (when (= 102 exit-status) (if nil (error "WakaTime Error (%s)" exit-status) (wakatime-prompt-api-key) (wakatime-call nil t))))
  (progn (kill-buffer (process-buffer process)) (let ((exit-status (process-exit-status process))) (when (and (not (= 0 exit-status)) (not (= 102 exit-status))) (error "WakaTime Error (%s)" exit-status)) (when (= 102 exit-status) (if nil (error "WakaTime Error (%s)" exit-status) (wakatime-prompt-api-key) (wakatime-call nil t)))))
  (if (memq (process-status process) (quote (exit signal))) (progn (kill-buffer (process-buffer process)) (let ((exit-status (process-exit-status process))) (when (and (not (= 0 exit-status)) (not (= 102 exit-status))) (error "WakaTime Error (%s)" exit-status)) (when (= 102 exit-status) (if nil (error "WakaTime Error (%s)" exit-status) (wakatime-prompt-api-key) (wakatime-call nil t))))))
  (when (memq (process-status process) (quote (exit signal))) (kill-buffer (process-buffer process)) (let ((exit-status (process-exit-status process))) (when (and (not (= 0 exit-status)) (not (= 102 exit-status))) (error "WakaTime Error (%s)" exit-status)) (when (= 102 exit-status) (if nil (error "WakaTime Error (%s)" exit-status) (wakatime-prompt-api-key) (wakatime-call nil t)))))
  (lambda (process signal) (when (memq (process-status process) (quote (exit signal))) (kill-buffer (process-buffer process)) (let ((exit-status (process-exit-status process))) (when (and (not (= 0 exit-status)) (not (= 102 exit-status))) (error "WakaTime Error (%s)" exit-status)) (when (= 102 exit-status) (if nil (error "WakaTime Error (%s)" exit-status) (wakatime-prompt-api-key) (wakatime-call nil t))))))(# "exited abnormally with code 2\n")

Go to the wakatime source file wakatime-mode.el, and find the position which the error happen.

(defun wakatime-call (command)
  "Call WakaTime COMMAND."
  (let*
    (
      (process-environment (if wakatime-python-path
                               (cons (format "PYTHONPATH=%s" wakatime-python-path) process-environment)
                             process-environment))
      (process
        (start-process
          "Shell"
          (generate-new-buffer " *WakaTime messages*")
          shell-file-name
          shell-command-switch
          command
        )
      )
    )

    (set-process-sentinel process
      (lambda (process signal)
        (when (memq (process-status process) '(exit signal))
          (kill-buffer (process-buffer process))
          (let ((exit-status (process-exit-status process)))
            (when (and (not (= 0 exit-status)) (not (= 102 exit-status)))
              (error "WakaTime Error (%s)" exit-status)
            )
          )
        )
      )
    )

    (set-process-query-on-exit-flag process nil)
  )
)

Find the origin wakatime-call function caller

(defun wakatime-save ()
  "Send save notice to WakaTime."
  (when (buffer-file-name (current-buffer))
    (wakatime-call (wakatime-client-command t))))

Execute (wakatime-client-command t) in *ielm* (M-x ielm)

ELISP> (wakatime-client-command t)
"/usr/bin/python2 /usr/local/bin/wakatime --file \"nil\" --write --plugin emacs-wakatime/1.0.2 --key e191899f-9e2a-4d00-8100-4e9f9523fedb --time 1476063658.33"

Here, we find that wakatime plugin executes a command in subprocess. So, we can execute in terminal manually:

➜  ~ /usr/bin/python2 /usr/local/bin/wakatime --file \"nil\" --write --plugin emacs-wakatime/1.0.2 --key e191899f-9e2a-4d00-8100-4e9f9523fedb --time 1476063658.33
Error: Could not read from config file /home/aborn/.wakatime.cfg

Solution

The really reason is Could not read from config file /home/aborn/.wakatime.cfg. Then we manually create the file /home/aborn/.wakatime.cfg with its content:

[settings]
api_key = e191899f-9e2a-4d00-8100-4e9f9523fedb

Note: pls replace api_key with your wakatime api_key.