Match data is constantly clobbered

[TinaRussell]

I know this package isn’t actively maintained, I just want to leave a record of all the effort I put into figuring out which one of my bazillion installed packages was causing this problem. (The match-data is incredibly difficult to debug.)

Try using edebug-defun with point in this function definition:

(defun tina/test-match-data ()
  (let ((string "Find the computer room"))
    (string-match "room" string)
    (equal (match-string 0 string) "room")))

Now evaluate (tina/test-match-data). While in Edebug, press T (edebug-trace-mode) or Shift+T (edebug-Trace-fast-mode).
If guide-key-mode is off, the result will be t.
If guide-key-mode is on, the result will be nil. (Setting guide-key/polling-time to a large number also works.)

It seems something—I think guide-key/format-guide-buffer—is changing the match data at every opportunity. Remember, developers: be mindful of your fluids and always use save-match-data! Thank you and good night!

[ysmolski]

I can feel your pain. I have spent wonderful two hours doing exactly what you did before me. #49

Would it be great to somehow mark such broken packages in MELPA to save others from the pain?
I have created an issue in purcell's config, I am not sure where else can I make noise to save others from the pain.