Biblatex and listings incompatibility...

Question

Does someone know why biblatex and listings are incompatible and if there is a way to fix it?

I have a Lyx document and whenever I insert program listings I get errors like:

 al trabajo de \citet{Fernandez2007}.
                                           Más adelante se describe la
The control sequence at the end of the top line
of your error message was never \def'ed. If you have
misspelled it (e.g., `\hobx'), type `I' and the correct
spelling (e.g., `I\hbox'). Otherwise just continue,
and I'll forget about whatever was undefined.

or like

 \printbibliography\newpage
                             {}
The control sequence at the end of the top line
of your error message was never \def'ed. If you have
misspelled it (e.g., `\hobx'), type `I' and the correct
spelling (e.g., `I\hbox'). Otherwise just continue,
and I'll forget about whatever was undefined.

This happens only when I add the use of package listings.

I am including biblatex like this:

\usepackage[natbib=true,style=alphabetic-verb,sorting=nty,hyperref,backend=bibtex8]{biblatex}

Any help will be very much appreciated.

Bests,

B.

Edit (more details): Since I've been asked an example, I actually don't have one. Because all I have to do is adding:

\usepackage{listings}

to my Latex preamble (I am using Lyx) to get these errors. I have not even inserted source code listings yet.

If I insert a source code listing using Lyx menu I will have the same problem since Lyx currently uses listings package and it will automatically insert listings package in the preamble.

This is really strange, because I don't see why when I insert listings that would undefine \citet or other commands. I just upgraded from Lyx 1.6.8 to Lyx 2.0.0 to see if this fixed something, but no. I also updated the MikTex packages but it does not fix anything.

Answer 1

This minimal example, following your description, shows that it can be compiled without that error message complaining about \citet being undefined:

\documentclass{article}
\usepackage[natbib=true,style=alphabetic-verb,sorting=nty,hyperref,backend=bibtex8]{biblatex}
\begin{document}
al trabajo de \citet{Fernandez2007}.
\end{document}

However, I can confirm, that the error

! Undefined control sequence.
l.4 al trabajo de \citet
                        {Fernandez2007}.

would occur if no options to biblatex are used, i.e. if I just write \usepackage{biblatex}. This doesn't depend on the listings package.

Answer 2

I already know that \citet is from natbib. Using natbib markup is mandatory on Lyx when one has included the biblatex module. That is why in biblatex package options I used natbib=true. That will in effect create aliases.

After trying a lot of things I solved my problem using biber backend instead of bibtex8 backend. Why this does solve the problem I don't know. Could be a character code problem?

Anyway, I am able now to use the listings package.

¡Thanks for your comments and help!