Hi Pedro,
Thanks, I did try the non-greedy capture and it didn't work. I'm actually
just realizing that it probably didn't work because it's not that it's
greedy, it's that "]{babel}"doesn't sufficiently constrain the contents
ahead of it.
Cheers,
Derek
On Thu, May 21, 2026 at 9:30 AM Pedro Andres Aranda Gutierrez <
[email protected]> wrote:
> Hi Derek,
>
> the ox-latex.el part can be simplified as
>
> (not (string-match "\\\\usepackage\\[\\(.*?\\)\\]{babel}" header)))
>
> That will make the regex stop before the ']' and is easier to read (at
> least for me-TM),
>
> Best,
> /PA
> ox-latex.el maintainer
>
>
> On Thu, 21 May 2026 at 15:30, Derek Chen-Becker <[email protected]>
> wrote:
>
>> Confirmed, against d34e34f3e.
>>
>> The replacement text of "utf8]{inputenc} \\usepackage[french, english"
>> makes it appear that the regex patterns used in
>> `org-latex-guess-babel-language' aren't sufficiently constrained. Checking
>> the regex, it's using "\\[.*\\]", which is why you're only seeing this when
>> you have more than one extra header (with only one, there's only one set of
>> braces).
>>
>> I took a look and think I have a fix but I want a second opinion. The
>> attached patch fixes the regex by changing the greedy match for the
>> language to one that only captures what's between the "[...]". I tried
>> using a non-greedy qualifier (".*?") and that didn't work, but I feel like
>> I always get tripped up by Elisp regex patterns. If someone has a better
>> suggestion for the regex I'm open to changing it.
>>
>> Owned.
>>
>> Cheers,
>>
>> Derek
>>
>> On Wed, May 20, 2026 at 11:41 AM <[email protected]> wrote:
>>
>>>
>>> With the following Org file
>>>
>>> ----------------------
>>> #
>>> * subtree
>>> :PROPERTIES:
>>> :EXPORT_LATEX_HEADER: \usepackage[utf8]{inputenc}
>>> :EXPORT_LATEX_HEADER+: \usepackage[french]{babel}
>>> :END:
>>>
>>> bak
>>> ----------------------
>>>
>>> upon subtree export (C-c C-e C-s lp), I get an error, the beginning of
>>> the
>>> backtrace of which is
>>>
>>> Debugger entered--Lisp error: (error "Invalid use of ‘\\’ in replacement
>>> text")
>>>
>>> org-latex-guess-babel-language("\\documentclass[11pt]{article}\n\n\n\\usepackage[utf8]{inputenc}
>>> \\usepackage[french]{babel}\n" (:export-options (subtree) :back-end
>>> #s(org-export-backend :name latex :parent nil :transcoders (... ...
>>> ... .
>>>
>>>
>>> This occurs with
>>>
>>> GNU Emacs 30.2 (build 1, x86_64-redhat-linux-gnu, GTK+ Version 3.24.43,
>>> cairo version 1.18.2) of 2025-08-18
>>>
>>> with either
>>>
>>> - a void .emacs and
>>>
>>> Org mode version 9.8.4 (9.8.4-2f6959 @
>>> /home/cochard/.emacs.d/elpa/org-9.8.2/)
>>>
>>> - a void .emacs and
>>>
>>> Org mode version 9.8.2 (9.8.2-2ef390 @
>>> /home/cochard/.emacs.d/elpa/org-9.8.2/)
>>>
>>> - emacs -Q and
>>>
>>> Org mode version 9.7.11 (release_9.7.11 @
>>> /usr/share/emacs/30.2/lisp/org/)
>>>
>>> For what it's worth: (1) the problem does not show up for every
>>> combination
>>> of
>>>
>>> :EXPORT_LATEX_HEADER:
>>> :EXPORT_LATEX_HEADER+:
>>>
>>> (2) I did not succeed in exhibiting the problem with a single
>>>
>>> :EXPORT_LATEX_HEADER:
>>>
>>> --
>>> EOST (École et Observatoire des Sciences de la Terre)
>>> ITE (Institut Terre & Environnement) | [email protected]
>>> 5 rue René Descartes | Phone: +33 (0)3 68 85 50 44
>>> F-67084 Strasbourg Cedex, France | bureau 110, ancien bât.
>>>
>>>
>>
>> --
>> +---------------------------------------------------------------+
>> | Derek Chen-Becker |
>> | GPG Key available at https://keybase.io/dchenbecker and |
>> | https://pgp.mit.edu/pks/lookup?search=derek%40chen-becker.org |
>> | Fngrprnt: EB8A 6480 F0A3 C8EB C1E7 7F42 AFC5 AFEE 96E4 6ACC |
>> +---------------------------------------------------------------+
>>
>>
>
> --
> Fragen sind nicht da, um beantwortet zu werden,
> Fragen sind da um gestellt zu werden
> Georg Kreisler
>
> "Sagen's Paradeiser" (ORF: Als Radiohören gefährlich war) => write BE!
> Year 2 of the New Koprocracy
>
>
--
+---------------------------------------------------------------+
| Derek Chen-Becker |
| GPG Key available at https://keybase.io/dchenbecker and |
| https://pgp.mit.edu/pks/lookup?search=derek%40chen-becker.org |
| Fngrprnt: EB8A 6480 F0A3 C8EB C1E7 7F42 AFC5 AFEE 96E4 6ACC |
+---------------------------------------------------------------+
