Re: wrong-type-argument stringp nil

[Colin Baxter]

Dear Eric,
>>>>> Eric S Fraga <e.fraga@ucl.ac.uk> writes:

    > On Friday, 19 Feb 2021 at 14:11, Colin Baxter wrote:
    >> I getting the Lisp error: (wrong-type-argument stringp nil) when
    >> I 'C-c C-c' the babel gnuplot source code "poynting", even though
    >> the pdf graph is produced correctly. Any help at debugging would
    >> be much appreciated.

    > Works fine for me.  No error.  I initially I thought maybe you
    > needed a horizontal line dividing the headings from the numbers
    > but works fine without.

    > What version of org are you using?

    > You could "M-x toggle-debug-on-error RET" to see where the error
    > happens?

Found the error! In my ~/.emacs, I have a defun

#+begin_src elisp
(defun cb/display-inline-images ()
  (condition-cl-case nil
      (org-display-inline-images)
    (error nil)))
#+end_src

Changing the 'condition-cl-case' to 'condition-case' removed the
error. Interestingly, debug on error using emacs-27.1 configured for
the lucid pointed explicitly to the defun, whereas emacs-27.1 configured
for gtk3 didn't! Any idea why that should be?

Best wishes,

Colin.