Re: babel perl issue

[Eric Schulte <schulte.eric@gmail.com>]

Achim Gratz <Stromeko@nexgo.de> writes:

> Eric Schulte writes:
>> See http://orgmode.org/manual/Languages.html for the documentation on
>> how to activate and disable org-babel languages.
>
> That actually produces the error:
>
> File mode specification error: (void-variable org-babel-tangle-lang-exts)
>
> as the OP has found out (and I can reproduce it).
>

Using this method of requiring languages,

    ;; emacs-lisp
    (org-babel-do-load-languages
      'org-babel-load-languages
      '((perl . t)))

Works for me without issue when called from a fresh emacs (-Q).  This is
the recommended way of adding support for a new language and should work
for the OP.

>
> The reason is that none of the ob-<lang>.el files do a (require
> ob-tangle), but try to change a defcustom in ob.tangle.el that is only
> declared, but not yet available at the time.

The two fixes seem to be either to either (1) add (require 'ob-tangle)
to all current and new language specific files, or (2) merge ob-tangle
into ob.el, so that they are both loaded by (require 'ob).  It is
unfortunate that because of the recursive require there is no way to
separate a single require'd entity across multiple files.

Option (2) seems most clean to me.  Unless anyone has a better idea I'll
make this change.

Best,

-- 
Eric Schulte
http://cs.unm.edu/~eschulte