Re: [O] [babel] Export problem (Wrong type argument: consp, nil)

[Eric Schulte]

>
> Question: Would it be possible to add the src-name in the error
> message?

Unfortunately the code block name is not known to the function (namely
`org-babel-merge-params') which throws errors when variables are not
assigned default values.  In fact this function may be called when there
are no code blocks present.  I think that this is why you ran into
problems trying to thread the code block info down into this error
message.

Another option may be to check when a code block is initially parsed to
ensure that all variables are assigned default parameters.  If the
checking is done initially then the code block name and position will be
known and could be included into the error message.  There exists a
function for checking code blocks (namely `org-babel-check-src-block'),
I've added a TODO to this function to add a check that all variables are
initialized.

>
> * Test
>
> #+begin_src emacs-lisp
> (ert-deftest test-org-babel/no-defaut-value-for-var ()
>   "Test that the absence of a default value for a variable does throw a proper
>   error."
>   (org-test-at-id "f2df5ba6-75fa-4e6b-8441-65ed84963627"
>     (org-babel-next-src-block)
>     (should-error (org-babel-execute-src-block))
>     :type 'error))
> #+end_src
>
> Though, I have 2 questions:
>
> - How can I differentiate between the clean error (with a message) and the one
>   which wasn't correctly trapped?  Based on the first line of a backtrace
>   (string comparison) or on the type of the error?  In the latter case, how
>   can I know what's the type of the current error thrown, and the one of the
>   error before your fix?
>

I believe Martyn answered this question

>
> - I wonder why we need twice the =org-babel-next-src-block= call, and
>   not only once in the =should-error= form.
>

I only see a single call to org-babel-next-src-block in the above test.

Thanks for working on this test, I look forward to adding it once it is
completed.

Cheers -- Eric

>
> Thanks.
>
> Best regards,
>   Seb

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