Re: [O] Bug: ditaa breaks export [7.8.03]

[Thomas Holst]

Hello orgers,

· Ian Dalton <address@hidden> wrote:

> When I run `emacs -q' and evaluate `(setq org-babel-load-languages
> '((ditaa . t)))', then try to export an org document to PDF, after
> answering yes to "Evaluate this ditaa code block", I get:
>
> Wrong type argument: stringp, nil
>
> Emacs  : GNU Emacs 24.0.93.1 (i486-pc-linux-gnu, GTK+ Version 2.20.1)
>  of 2012-02-22 on cw-bkp0, modified by Debian
> Package: Org-mode version 7.8.03

I can confirm this.

A little investigation shows that there are two definitions for
`org-ditaa-jar-path':

- in =lisp/ob-ditaa.el=:
  #+begin_src emacs-lisp
    (defcustom org-ditaa-jar-path nil
      "Path for the ditaa jar file."
      :group 'org-babel
      :type 'string)
  #+end_src

  This results in nil and so the error occurs.
  
- in =lisp/org-exp-blocks.el=
  #+begin_src emacs-lisp
    (defvar org-ditaa-jar-path (expand-file-name
                            "ditaa.jar"
                            (file-name-as-directory
                             (expand-file-name
                              "scripts"
                              (file-name-as-directory
                               (expand-file-name
                                "../contrib"
                                (file-name-directory (or load-file-name 
buffer-file-name)))))))
      "Path to the ditaa jar executable.")
  #+end_src

  On my machine this results in the correct path.

So the value of `org-ditaa-jar-path' depends on the loading sequence of
el-files.

A quick solution for OP would be to the set the path

#+begin_src emacs-lisp
  (setq org-ditaa-jar-path "<path-to-ditaa-jar>")
#+end_src

I am not too deep into dependencies of org files, but ob-ditaa.el could
require org-exp-blocks and skip the definition of `org-ditaa-jar-path'.
Or vice versa.

HTH
-- 
Mit freundlichen Grüßen / Best regards 

Thomas