How to export a reference to a #begin_src block to LaTeX

Question

I'm exporting an ORG file to LaTeX with org-latex-listings set to t. The file contains some source listings, and I want to insert some references to them.

In the generated TEX file, the reference names included in \ref seems to be translated by org-mode, but the label option of \lstset is keept as is. This way, pdflatex can't find the correct reference and gives the message LaTeX Warning: There were undefined references.

Here is an example of a MWE:

#+latex_header: \usepackage{listings}
First simple java program in listing [[thesourcelisting]]
#+name: thesourcelisting
#+caption: Simple java program
#+BEGIN_SRC java
public static void main(String[] args){
  System.exit(0);
}
#+END_SRC

When exported as a LaTeX file (C-c C-e l t), I got

% Created 2016-10-18 mar 14:50
\documentclass[11pt]{article}
\usepackage[utf8]{inputenc}
\usepackage[T1]{fontenc}
\usepackage{fixltx2e}
\usepackage{graphicx}
\usepackage{grffile}
\usepackage{longtable}
\usepackage{wrapfig}
\usepackage{rotating}
\usepackage[normalem]{ulem}
\usepackage{amsmath}
\usepackage{textcomp}
\usepackage{amssymb}
\usepackage{capt-of}
\usepackage{hyperref}
\usepackage{listings}

\author{alvaro}
\date{\today}
\title{}
\hypersetup{
 pdfauthor={alvaro},
 pdftitle={},
 pdfkeywords={},
 pdfsubject={},
 pdfcreator={Emacs 25.1.2 (Org mode 8.3.6)}, 
 pdflang={English}}
\begin{document}

\tableofcontents

First simple java program in listing \ref{orgsrcblock1}
\lstset{language=java,label=thesourcelisting,caption={Simple java program},captionpos=b,numbers=none}
\begin{lstlisting}
public static void main(String[] args){
  System.exit(0);
}
\end{lstlisting}
\end{document}

The original name thesourcelisting is translated to orgsrcblock1 in the \ref command, but not in the \lstset command.

I'm using GNU Emacs 25.1.2.

NickD NickD · Accepted Answer · 2016-11-19T05:09:20

Try setting org-latex-prefer-user-labels to t.

The doc string of the variable says in part (do C-h v org-latex-prefer-user-labels RET to get the whole thing):

Use user-provided labels instead of internal ones when non-nil.

When this variable is non-nil, Org will use the value of CUSTOM_ID property, NAME keyword or Org target as the key for the \label commands generated.

By default, Org generates its own internal labels during LaTeX export. This process ensures that the \label keys are unique and valid, but it means the keys are not available in advance of the export process.

How to export a reference to a #begin_src block to LaTeX

1 Answers